How to update and save Excel workbook

Hi

i should update workbook with some raw data and should savethat workbook for sharepoint purpose

i need code in c# for updating workbook with data and save that workbook.if file already exists it should override the content.not the whole file.


Please help me in resolving this issue


Thanks and Regards
Vinay kumar

Here is an example but in vb.net that is easily changeable to C#
http://vbforums.com/showthread.php?t=442132