Take a look at the following guide and see if it's any help: Restoring files using Previous Versions
Using Previous Versions it should be possible to restore the file to how it was before it was overwritten.
Hope that helps!
December 4, 2012 10:52:46 PM
Previous Versions will only be available if you have previously enabled VSS (Volume Shadow Copy Services) on the volume that the file was located on, it's not enabled by default on Server 2003.