These files are User Mailbox (Database) files. You can determine who these database files belong to by the GroupWise FID (File ID). In this case, USERQOD.DB, QOD is the GroupWise FID. For the file USERXW9.DB, the FID would be XW9.
If you have a very large amount of Users in the Post Office, it will be dificult having to look through the details of each Users GroupWise info. Another way you can do look up the info is through an NLIST search.
Make sure that you are are at a DOS Prompt and your context is correct, then type the following...
NLIST USER WHERE "NGW: File ID" EQ <FID> /S
Replace <FID> with the Users GroupWise FID.
Good Luck!