>...Also, is there
>anyway to prevent them from expiring (give them a longer retention
>period) ...

Unfortunately, the product does not allow you to adjust the retention of
individual Archive files: you can change them all, though.  From my notes:

Archived files, retention period,       'UPDate COpygroup DomainName SetName
 update                                         ClassName Type=Archive
                                                RETVer=N_Days|NOLimit'
                                        where RETVer specifies the retention
                                        period, and can be 0-9999 days, or
                                        "NOLimit".
                                        Default: 365 days.
                                        Effect: Changing RETVer causes any
                                        newly-archived files to pick up the new
                                        retention value, and previously-archived
                                        files also get the new retention value,
                                        because of their binding to the changed
                                        management class. (The TSM database
                                        Archives table contains an Archive_Date
                                        column: there is no "Expiration_Date"
                                        column, and so the archived files
                                        conform to whatever the prevailing
                                        management class retention rules are at
                                        the time. So if you extend your
                                        retention policy, it pertains to all
                                        archive files, old and new.)

  Richard Sims, BU