[Exim] forward mails in subfolder (maildirs)

hello

i'm a newbie to exim and couldn't figure out, how i can
forward emails form a mailinglist (like this :-) into a subfolder
of my maildir-directory. for instance:

when the mailheader addresses to: exim-users@???
it should go to folder <mymaildir>\exim-users.

sorry for beeing so stupid, but i couldn't figure it out from the docs.

kind regards

daniel