I don't know if this will help you or not...

Forces Microsoft Excel to register itself and then quit.
Use this switch when you want Microsoft Excel 97 to
rewrite all of its registry keys and reassociate itself
with Microsoft Excel files, such as workbooks, charts,
and add-ins.
Start, run,
C:Program FilesMicrosoft OfficeOfficeExcel.exe /regserver


taken from:

http://support.microsoft.com/default...;EN-US;q159474

Tom