delete/archive old mail

[sottilette at rfx.it]

Hi everybody,
 		I store user's mail in the old mbox format.
I have many scripts to manage users that works fine with mbox.
I use the very old Expire_mail.pl script to delete mail older than NN days 
for selected users (nightly cron job). Still works fine with my CentOS 
dovecot-2.0.16.
Now I want move the mail to a sort of archive folder instead of 
simply deleting it from the inbox for some users.
Is there a similar script or some simple triks?

Thanks, F.