This solution was posted by John Botha in 2001 in a vba addins news
group. I have used it when I got into a similar mess and it worked
about 30% of the time. I was using Excel 2000 at the time.

1.Get a binary editor. You can easily get a freeware binary editor.
2.Make a new Excel workbook, set a password in VBA Properties Dialog
3.Save the workbook as an *.xls file
4.Open the xls file with the Unknown password in the binary editor
5.Open the xls file with the password we've created in step 2. Also
with the binary editor
6.Search using the binary editor's in both the open files for "DPB"
7.When you find this, there wil be a code attached to this and you will
also find CMG code above and a GC code beneath
8.Now all you do is to replace this section of code inr the xls file
which you don't
know the password for with the password you know
9.Save the file and run Excel and open the book with the password
you've entered in step 2
10. Always make a backup of the file with the UNKNOWN password, because
editing with an binary editor can be fatal.