The sample demonstrates how to calculate formulas

using System;
using System.IO;
using System.Windows.Forms;
using Spire.Xls;

namespace DataCalculateWithFormulas
{
    class Program
    {
        static void Main(string[] args)
        {
            using (Stream buffer = WriteFormulas())
            {
                //load
                Workbook workbook = new Workbook();
                workbook.LoadFromStream(buffer);

                //calculate formula
                Object b3 = workbook.CaculateFormulaValue("=Sheet1!$B$3");
                Object c3 = workbook.CaculateFormulaValue("=Sheet1!$C$3");
                String formula = "=Sheet1!$B$3 + Sheet1!$C$3";
                Object value = workbook.CaculateFormulaValue(formula);
                String message
                    = String.Format("Sheet1!$B$3 = {0}, Sheet1!$C$3 = {1}, {2} = {3}", b3, c3, formula.Substring(1), value);
                MessageBox.Show(message, "Calculate Formulas");
            }
        }
        private static Stream WriteFormulas()
        {
            //Create Excel files

            Workbook workbook = new Workbook();
            Worksheet sheet = workbook.Worksheets[0];//it's the first sheet of the worksheets

            int currentRow = 1;
            string currentFormula = string.Empty;
            sheet.SetColumnWidth(1, 32);//SetColumnWidth(columnIndex,width);
            sheet.SetColumnWidth(2, 16);
            sheet.SetColumnWidth(3, 16);
            sheet.Range[currentRow++, 1].Value = "Examples of formulas :";
            sheet.Range[++currentRow, 1].Value = "Test data:";

            CellRange range = sheet.Range["A1"];
            range.Style.Font.IsBold = true;
            range.Style.FillPattern = ExcelPatternType.Solid;
            range.Style.KnownColor = ExcelColors.LightGreen1;
            range.Style.Borders[BordersLineType.EdgeBottom].LineStyle = LineStyleType.Medium;

            //test data
            sheet.Range[currentRow, 2].NumberValue = 7.3;
            sheet.Range[currentRow, 3].NumberValue = 5; ;
            sheet.Range[currentRow, 4].NumberValue = 8.2;
            sheet.Range[currentRow, 5].NumberValue = 4;
            sheet.Range[currentRow, 6].NumberValue = 3;
            sheet.Range[currentRow, 7].NumberValue = 11.3;

            MemoryStream buffer = new MemoryStream();
            workbook.SaveToStream(buffer);
            buffer.Position = 0;
            return buffer;
        }
    }
}

Imports System.IO
Imports System.Windows.Forms
Imports Spire.Xls

Module Module1
    Private Function WriteFormulas() As Stream
        Dim workbook As Workbook = New Workbook()
        Dim sheet As Worksheet = workbook.Worksheets(0)

        Dim currentRow As Integer = 1
        Dim currentFormula As String = String.Empty

        sheet.SetColumnWidth(1, 32)
        sheet.SetColumnWidth(2, 16)
        sheet.SetColumnWidth(3, 16)

        currentRow = currentRow + 1
        sheet.Range(currentRow, 1).Value = "Examples of formulas :"
        currentRow = currentRow + 1
        sheet.Range(currentRow, 1).Value = "Test data:"

        Dim range As CellRange = sheet.Range("A1")
        range.Style.Font.IsBold = True
        range.Style.FillPattern = ExcelPatternType.Solid
        range.Style.KnownColor = ExcelColors.LightGreen1
        range.Style.Borders(BordersLineType.EdgeBottom).LineStyle = LineStyleType.Medium

        'test data
        sheet.Range(currentRow, 2).NumberValue = 7.3
        sheet.Range(currentRow, 3).NumberValue = 5

        sheet.Range(currentRow, 4).NumberValue = 8.2
        sheet.Range(currentRow, 5).NumberValue = 4
        sheet.Range(currentRow, 6).NumberValue = 3
        sheet.Range(currentRow, 7).NumberValue = 11.3

        Dim buffer As New MemoryStream()
        workbook.SaveToStream(buffer)
        buffer.Position = 0

        Return buffer
    End Function
    Sub Main()
        Using buffer As Stream = WriteFormulas()
            'load
            Dim workbook As New Workbook()
            workbook.LoadFromStream(buffer)

            'calculate formula
            Dim b3 As Object = workbook.CaculateFormulaValue("=Sheet1!$B$3")
            Dim c3 As Object = workbook.CaculateFormulaValue("=Sheet1!$C$3")
            Dim formula As String = "=Sheet1!$B$3 + Sheet1!$C$3"
            Dim value As Object = workbook.CaculateFormulaValue(formula)
            Dim message As String = _
                String.Format("Sheet1!$B$3 = {0}, Sheet1!$C$3 = {1}, {2} = {3}", b3, c3, formula.Substring(1), value)
            MessageBox.Show(message, "Calculate Formulas")
        End Using
    End Sub
End Module

Not needing to have Microsoft Excel installed on the machine, The Spire.DataExport can create Excel spreadsheet. This sample demonstrates how to add formulas into xls.

private void button1_Click(object sender, EventArgs e)
{
    Spire.DataExport.XLS.CellExport cellExport5
        = new Spire.DataExport.XLS.CellExport();

    cellExport5.ActionAfterExport = Spire.DataExport.Common.ActionType.OpenView;
    cellExport5.ColumnsWidth.AddRange(new object[] {
                                                            "100",
                                                            "200"});
    cellExport5.DataExported = false;
    cellExport5.DataFormats.CultureName = "zh-CN";
    cellExport5.DataFormats.Currency = "￥#,###,##0.00";
    cellExport5.DataFormats.DateTime = "yyyy-M-d H:mm";
    cellExport5.DataFormats.Float = "#,###,##0.00";
    cellExport5.DataFormats.Integer = "#,###,##0";
    cellExport5.DataFormats.Time = "H:mm";
    cellExport5.FileName = "formula.xls";
    cellExport5.SheetOptions.AggregateFormat.Font.Name = "Arial";
    cellExport5.SheetOptions.CustomDataFormat.Font.Name = "Arial";
    cellExport5.SheetOptions.DefaultFont.Name = "Arial";
    cellExport5.SheetOptions.FooterFormat.Font.Name = "Arial";
    cellExport5.SheetOptions.HeaderFormat.Font.Name = "Arial";
    cellExport5.SheetOptions.HyperlinkFormat.Font.Color = Spire.DataExport.XLS.CellColor.Blue;
    cellExport5.SheetOptions.HyperlinkFormat.Font.Name = "Arial";
    cellExport5.SheetOptions.HyperlinkFormat.Font.Underline = Spire.DataExport.XLS.XlsFontUnderline.Single;
    cellExport5.SheetOptions.NoteFormat.Alignment.Horizontal = Spire.DataExport.XLS.HorizontalAlignment.Left;
    cellExport5.SheetOptions.NoteFormat.Alignment.Vertical = Spire.DataExport.XLS.VerticalAlignment.Top;
    cellExport5.SheetOptions.NoteFormat.Font.Bold = true;
    cellExport5.SheetOptions.NoteFormat.Font.Name = "Tahoma";
    cellExport5.SheetOptions.NoteFormat.Font.Size = 8F;
    cellExport5.SheetOptions.TitlesFormat.Font.Bold = true;
    cellExport5.SheetOptions.TitlesFormat.Font.Name = "Arial";

    ushort currentRow = 1;
    string currentFormula = string.Empty;

    Spire.DataExport.XLS.Cell cell = null;

    cellExport5.Cells.Clear();
    cellExport5.SetColumnWidth(1, 32);
    cellExport5.SetColumnWidth(2, 16);
    cellExport5.SetColumnWidth(3, 16);

    cell = cellExport5.AddString(1, currentRow++, "Examples of formulas :");
    cell.Format.Font.Bold = true;
    cell.Format.FillStyle.Background = Spire.DataExport.XLS.CellColor.LightGreen;
    cell.Format.FillStyle.Pattern = Spire.DataExport.XLS.Pattern.Solid;
    cell.Format.Borders.Bottom.Style = Spire.DataExport.XLS.CellBorderStyle.Medium;

    cell = cellExport5.AddString(1, ++currentRow, "Test data:");
    cell.Format.Font.Bold = true;
    cell.Format.FillStyle.Background = Spire.DataExport.XLS.CellColor.LightGreen;
    cell.Format.FillStyle.Pattern = Spire.DataExport.XLS.Pattern.Solid;
    cell.Format.Borders.Bottom.Style = Spire.DataExport.XLS.CellBorderStyle.Medium;

    //test data
    cellExport5.AddNumeric(2, currentRow, 7.3);
    cellExport5.AddNumeric(3, currentRow, 5);
    cellExport5.AddNumeric(4, currentRow, 8.2);
    cellExport5.AddNumeric(5, currentRow, 4);
    cellExport5.AddNumeric(6, currentRow, 3);
    cellExport5.AddNumeric(7, currentRow++, 11.3);


    cell = cellExport5.AddString(1, ++currentRow, "Formulas");
    cell.Format.Font.Bold = true;
    cell.Format.FillStyle.Background = Spire.DataExport.XLS.CellColor.LightGreen;
    cell.Format.FillStyle.Pattern = Spire.DataExport.XLS.Pattern.Solid;
    cell.Format.Borders.Bottom.Style = Spire.DataExport.XLS.CellBorderStyle.Medium;

    cell = cellExport5.AddString(2, currentRow, "Results");
    cell.Format.Font.Bold = true;
    cell.Format.FillStyle.Background = Spire.DataExport.XLS.CellColor.LightGreen;
    cell.Format.FillStyle.Pattern = Spire.DataExport.XLS.Pattern.Solid;
    cell.Format.Borders.Bottom.Style = Spire.DataExport.XLS.CellBorderStyle.Medium;

    //str.
    currentFormula = "=\"hello\"";
    cellExport5.AddString(1, ++currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow, "=\"hello\"");
    cellExport5.AddFormula(3, currentRow, "=\"" + new string(new char[] { '\u4f60', '\u597d' }) + "\"");



    //int.
    currentFormula = "=300";
    cellExport5.AddString(1, ++currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow, currentFormula);

    // float
    currentFormula = "=3389.639421";
    cellExport5.AddString(1, ++currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow, currentFormula);

    //bool.
    currentFormula = "=false";
    cellExport5.AddString(1, ++currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow, currentFormula);

    currentFormula = "=1+2+3+4+5-6-7+8-9";
    cellExport5.AddString(1, ++currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow, currentFormula);

    currentFormula = "=33*3/4-2+10";
    cellExport5.AddString(1, ++currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow, currentFormula);


    // sheet reference
    currentFormula = "=Sheet1!$B$3";
    cellExport5.AddString(1, ++currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow, currentFormula);

    // sheet area reference
    currentFormula = "=AVERAGE(Sheet1!$D$3:G$3)";
    cellExport5.AddString(1, ++currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow, currentFormula);

    // Functions
    currentFormula = "=Count(3,5,8,10,2,34)";
    cellExport5.AddString(1, ++currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);


    currentFormula = "=NOW()";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=SECOND(11)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=MINUTE(12)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=MONTH(9)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=DAY(10)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=TIME(4,5,7)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=DATE(6,4,2)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=RAND()";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=HOUR(12)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=TEXT(\"world\", \"$d\")";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=MOD(5,3)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=WEEKDAY(3)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=YEAR(23)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=NOT(true)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=OR(true)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=AND(TRUE)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=VALUE(30)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=LEN(\"world\")";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=MID(\"world\",4,2)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=ROUND(7,3)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=SIGN(4)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=INT(200)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=ABS(-1.21)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=LN(15)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=EXP(20)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=SQRT(40)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=PI()";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=COS(9)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=SIN(45)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=MAX(10,30)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=MIN(5,7)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=AVERAGE(12,45)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=SUM(18,29)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=IF(4,2,2)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    currentFormula = "=SUBTOTAL(3,Sheet1!B2:E3)";
    cellExport5.AddString(1, currentRow, currentFormula);
    cellExport5.AddFormula(2, currentRow++, currentFormula);

    cellExport5.SaveToFile();
}

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    Dim cellExport5 As Spire.DataExport.XLS.CellExport
    cellExport5 = New Spire.DataExport.XLS.CellExport

    cellExport5.ActionAfterExport = Spire.DataExport.Common.ActionType.OpenView
    cellExport5.ColumnsWidth.AddRange(New Object() {"100", "200"})
    cellExport5.DataExported = False
    cellExport5.DataFormats.CultureName = "zh-CN"
    cellExport5.DataFormats.Currency = "￥#,###,##0.00"
    cellExport5.DataFormats.DateTime = "yyyy-M-d H:mm"
    cellExport5.DataFormats.Float = "#,###,##0.00"
    cellExport5.DataFormats.Integer = "#,###,##0"
    cellExport5.DataFormats.Time = "H:mm"
    cellExport5.FileName = "formula.xls"
    cellExport5.SheetOptions.AggregateFormat.Font.Name = "Arial"
    cellExport5.SheetOptions.CustomDataFormat.Font.Name = "Arial"
    cellExport5.SheetOptions.DefaultFont.Name = "Arial"
    cellExport5.SheetOptions.FooterFormat.Font.Name = "Arial"
    cellExport5.SheetOptions.HeaderFormat.Font.Name = "Arial"
    cellExport5.SheetOptions.HyperlinkFormat.Font.Color = Spire.DataExport.XLS.CellColor.Blue
    cellExport5.SheetOptions.HyperlinkFormat.Font.Name = "Arial"
    cellExport5.SheetOptions.HyperlinkFormat.Font.Underline = Spire.DataExport.XLS.XlsFontUnderline.Single
    cellExport5.SheetOptions.NoteFormat.Alignment.Horizontal = Spire.DataExport.XLS.HorizontalAlignment.Left
    cellExport5.SheetOptions.NoteFormat.Alignment.Vertical = Spire.DataExport.XLS.VerticalAlignment.Top
    cellExport5.SheetOptions.NoteFormat.Font.Bold = True
    cellExport5.SheetOptions.NoteFormat.Font.Name = "Tahoma"
    cellExport5.SheetOptions.NoteFormat.Font.Size = 8.0!
    cellExport5.SheetOptions.TitlesFormat.Font.Bold = True
    cellExport5.SheetOptions.TitlesFormat.Font.Name = "Arial"

    Dim currentRow As Integer = 1
    Dim firstCol As UInt16 = Convert.ToUInt16(1)
    Dim secondCol As UInt16 = Convert.ToUInt16(2)
    Dim currentFormula As String = String.Empty

    Dim cell As cell = Nothing

    cellExport5.Cells.Clear()
    cellExport5.SetColumnWidth(System.Convert.ToUInt16(1), System.Convert.ToUInt16(32))
    cellExport5.SetColumnWidth(System.Convert.ToUInt16(2), System.Convert.ToUInt16(16))
    cellExport5.SetColumnWidth(System.Convert.ToUInt16(3), System.Convert.ToUInt16(16))

    cell = cellExport5.AddString(System.Convert.ToUInt16(1), System.Convert.ToUInt16(currentRow), "Examples of formulas :")
    currentRow += 1
    cell.Format.Font.Bold = True
    cell.Format.FillStyle.Background = CellColor.LightGreen
    cell.Format.FillStyle.Pattern = Pattern.Solid
    cell.Format.Borders.Bottom.Style = CellBorderStyle.Medium

    cell = cellExport5.AddString(System.Convert.ToUInt16(1), System.Convert.ToUInt16(currentRow), "Test data:")
    currentRow += 1
    cell.Format.Font.Bold = True
    cell.Format.FillStyle.Background = CellColor.LightGreen
    cell.Format.FillStyle.Pattern = Pattern.Solid
    cell.Format.Borders.Bottom.Style = CellBorderStyle.Medium

    'test data
    cellExport5.AddNumeric(System.Convert.ToUInt16(2), System.Convert.ToUInt16(currentRow), 7.3)
    cellExport5.AddNumeric(System.Convert.ToUInt16(3), System.Convert.ToUInt16(currentRow), 5)
    cellExport5.AddNumeric(System.Convert.ToUInt16(4), System.Convert.ToUInt16(currentRow), 8.2)
    cellExport5.AddNumeric(System.Convert.ToUInt16(5), System.Convert.ToUInt16(currentRow), 4)
    cellExport5.AddNumeric(System.Convert.ToUInt16(6), System.Convert.ToUInt16(currentRow), 3)
    cellExport5.AddNumeric(System.Convert.ToUInt16(7), System.Convert.ToUInt16(currentRow), 11.3)
    currentRow += 1
    currentRow += 1


    cell = cellExport5.AddString(Convert.ToUInt16(1), Convert.ToUInt16(currentRow), "Formulas")
    cell.Format.Font.Bold = True
    cell.Format.FillStyle.Background = CellColor.LightGreen
    cell.Format.FillStyle.Pattern = Pattern.Solid
    cell.Format.Borders.Bottom.Style = CellBorderStyle.Medium

    cell = cellExport5.AddString(secondCol, Convert.ToUInt16(currentRow), "Results")
    currentRow += 1
    cell.Format.Font.Bold = True
    cell.Format.FillStyle.Background = CellColor.LightGreen
    cell.Format.FillStyle.Pattern = Pattern.Solid
    cell.Format.Borders.Bottom.Style = CellBorderStyle.Medium

    'str.
    currentFormula = "=""hello"""
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), "=""hello""")
    cellExport5.AddFormula(Convert.ToUInt16(3), Convert.ToUInt16(currentRow), "=""" & ChrW(20320) & ChrW(22909) + """")
    currentRow += 1



    'int.
    currentFormula = "=300"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    ' float
    currentFormula = "=3389.639421"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1


    'bool.
    currentFormula = "=false"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=1+2+3+4+5-6-7+8-9"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=33*3/4-2+10"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    ' sheet reference
    currentFormula = "=Sheet1!$B$3"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    ' sheet area reference
    currentFormula = "=AVERAGE(Sheet1!$D$3:G$3)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    ' Functions
    currentFormula = "=Count(3,5,8,10,2,34)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1


    currentFormula = "=NOW()"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=SECOND(11)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=MINUTE(12)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=MONTH(9)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=DAY(10)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=TIME(4,5,7)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=DATE(6,4,2)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=RAND()"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=HOUR(12)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=TEXT(""world"", ""$d"")"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=MOD(5,3)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=WEEKDAY(3)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=YEAR(23)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=NOT(true)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=OR(true)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=AND(TRUE)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=VALUE(30)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=LEN(""world"")"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=MID(""world"",4,2)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=ROUND(7,3)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=SIGN(4)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=INT(200)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=ABS(-1.21)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=LN(15)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=EXP(20)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=SQRT(40)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=PI()"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=COS(9)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=SIN(45)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=MAX(10,30)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=MIN(5,7)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=AVERAGE(12,45)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=SUM(18,29)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=IF(4,2,2)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1

    currentFormula = "=SUBTOTAL(3,Sheet1!B2:E3)"
    cellExport5.AddString(firstCol, Convert.ToUInt16(currentRow), currentFormula)
    cellExport5.AddFormula(secondCol, Convert.ToUInt16(currentRow), currentFormula)
    currentRow += 1
    cellExport5.SaveToFile()
End Sub