I read the responses to AndrewMeads question as my problem was similar.

From within FrontPage '03, I am hyperlinking an entry on a .htm page to open
a specified Excel file and then open 1 of 3 worksheets within the file. I
tried the direct responses like: .xls#'sheet 1'!A2 and .xls#'sheet1'!A2click
me</A but,
1. I get an error message "Reference not valid" and when I try the 2 other
hyperlinks in Preview mode, get the same error message, but the worksheet
that was active last is what is open and not the selected worksheet.

I also tried this outside of FrontPage and got the same results.... am I
doing something wrong or not getting something here?