actualy that is a great idea, cos when u play a season with a tweaked roster the wins and losses stuff up by editing them in the dbf you could make them more realistic
As Jerry said, make sure you are editing the correct files - the ones in your Franchises' save slot - the file you need to edit is teams.dbf. See the Teams.dbf Editing Guide for more details.
To be honest, I've never tried changing my win/loss record. However, those are the only fields you could change that would affect the standings.
The only thing I could suggest would be to make sure you edit the other teams so that their records are consistent with yours (ie so the record doesn't show you both won a game).