[Exim] maybe OT: filtered IMAP delivery

I'm using exim with cyrus-imap. I want
exim to deliver certain mails into
different imap-folders. (e.g. the exim
mailing list in an exim folder)
I'm not quite sure how to do that...
...my first guess was the .forward filter
or maybe a procmail filter but I can't
see how that can work with imap folders.

Has anyone done this before?
Any comments?
--
Torsten