Hi Michael.
My answer is in VB :)

Work with objects !!!
(Firstly you might want to place the code as in the "dont sample" so it will
be easy to debug, but after you make it work - use objects).

Do:
Dim xlsApp As Object
Set xlsApp = CreateObject("Excel.Application")

Dont:
Dim xlsApp As Excel.Application

HTH
Guy

"Michael" wrote in message
...
Hello,

I have made a windows application in C#, and i automate Excel to print
some data.

On my dev machine i have Office XP installed (Excel 2002) so i get the COM
dll from it, version 10.0 object library.

The application is running well on machines with Excel 2002, the xls file
open and data is inserted in the cells.

But with Excel 2000 the process fail when opening the workbook.

The exception is :
System.NullReferenceException : Object not set to an instance of an object
at Excel.workbooks.Open(...)

Object oMissing = System.Reflection.Missing.Value;

//monXLS = appliXLS.Workbooks.Open(nomFichier, oMissing, oMissing,
oMissing, oMissing, oMissing, oMissing, oMissing, oMissing, oMissing,
oMissing, oMissing, oMissing, oMissing, oMissing);

monXLS = appliXLS.Workbooks.Open(nomFichier, 0, false, 5, "", "", true,
Excel.XlPlatform.xlWindows, "", false, false, 0, false, 0, true);



Is there a way to make it work for both version 2000 and 2002 ?