ExcelBanter - Inserting an analysis toolpak function in a Cell with C#

First of all, greetings to every one.

I have to say that I'm new to the Microsoft Office programming. I use
Excel 2003 US with analysis toolpak loaded and VS.net 2005.

I'm making a little programme in C# to write formulas into Excel sheet
cells. It works just fine with the basics formulas but with the
formulas from the analysis toolpak they are not understood, I get the
#NAME? message.

The thing that I don't understand is that when I write the formula
(=ISODD(3) for exemple) with my programe and open the xls file with
excel, double click on the cell and press "enter" the cell is
recalculated and put correctly the "false" indication.

What should I do have the cell with the analysis toolpak correctly
writen or evaluated ?

Many thank's for the help and for your answers

Clair

PS : this is the methode I use the modify a Cell :

private Excel.Range excelRange = null;

..
..
..

public void modifCell(int line, int row, string value)
{
excelRange = (Excel.Range)excelCurrentSheet.Cells[line, row];
excelRange.Cells.Clear();
excelRange.Cells.FormulaLocal = value;
excelRange.Cells.Calculate();
}