A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
Hi,
Chip Pearson has a page on how to do this
http://www.cpearson.com/excel/CreatingCOMAddIn.aspx
EDIT>>>I assume this has been marked as a proposed answer in error, I only responded 5 minutes ago the OP won't even have time to have read it yet!!!
If this post answers your question, please mark it as the Answer.
Mike H