If you are using MSDE, by default, BackupExec creates a BEDB.BAK file every night.
As long as you have the most recent MSDB.BAK and the \Catalogs directory on a tape, you can install BackupExec, inventory the tape, catalog it, restore the BAK file and Catalogs dir, then see http://seer.support.veritas.com/docs/260054.htm to recover your configuration and http://seer.support.veritas.com/docs/272886.htm to force BackupExec to reindex the catalog so all you old tapes are avaiable for restore