It looks like you're trying to separate tapes by pool. You could try something like this:

my @daily_pool = `mminfo -av -r 'volume, savetime' -q 'pool=DailySecOf
+fSite' -t '3 weeks ago'`;
my @monthly_pool = `mminfo -av -r 'volume, savetime' -q 'pool=MonthlyO
+ffSite' -t '3 weeks ago'`;
[download]

There is a great Listserv forum for NetWorker where you can get all sorts of help with NetWorker and how to use programming languages around it. Check out these listserv archives for more information.