You might be completely out of luck, but there are a few things to try. First, copy the database up to a server, if you can. Copy it outside of the Domino data directory, somewhere like c:\temp. From a DOS prompt, you need to navigate to your Domino program directory (C:\Domino, usually). From there, run “ncompact.exe c:\temp\filename.nsf -C”. This will do a copy style compact on your file. You can also try running nfixup.exe and nupdall.exe on the file, but the compact is the key. If the file is recoverable, compact will do it.
The file does not need to be copied to the server. Just get a copy of ncompact.exe on your local machine and run it from there. This is a lighter approach and one your server admins would like better.
I agree that a copy style compact is a good approach.