Hi
I am having a similar problem to you i think.
I have an Excel book filled with Macros that don't want to operate within the IE Structure(It seems also not to Like PivotTables). Our Idea was to open the Workbook in the Excel Structure rather than IE. A way to achieve this is provided at
http://www.whirlywiryweb.com/q%2Fofficedocs.asp
which gives a Javascript routine for opening the Excel Application.
This seemed to work fine for Excel 2003, but not Excel 97(Which is our Standard).
Hope this helps somewhat
David