Can I fix Corrupt Win2k backup file?

I fell fowl of Microsoft Knowledgebase 269826 by backing up to a .bkf file of >4GB on a FAT32 drive.
I then lost the originals by reformatting my Win2k machine and have now lost my last 3 years work!
If i try to restore I get the error message:
"The backup file is unusable. You must erase it, or choose another file. "
The backup consists of a 'normal' backup and then a small incremental backup that pushed it over the 4GB edge. I did get an error at the time but I thought i related to one particular .pst file which I then separately backed up (and restored successfully).
Can I perhaps strip out the 2nd backup to reduce the file size and restore it?
Any other possible methods?
Regards
Dave