[Exim] Wishlist

Hi,

i'm missing i neat feature in exims filter language, a possibility to
add a header to the message, scenerio:

I'm subscribed to list@???, and filter it with exim-filters, to
deliver it to a special maildir-folder, but these list does not add a
Reply-To: header automaticly, so i would like to add the header in my
filterfile, because i'm lazy sometimes, and hit the wrong button for
replying ;)

Comments?
Risks?
Did i miss the feature in the documentations?


ciao