dynamic naming & creation of mailboxes

Hi folks.

I'm looking to create a new sub-folder / day setup for an mailbox that gets
a couple of hundred messages every day.  Then automatically deliver messages
to today's folder.

I've checked the mailing list archives, googled, and read the Sieve RFC.  It
looks to me like there's now way to do this easily with Sieve.

My current solution is a perl script run by a cron job that makes the
sub-folder and writes a new .sieve.

Is there a better way to do this?