Generate constant address file

May I inquire if there is a way I could instruct Procmail to add all
addresses from each message that comes by to a file?  Yes, pretty similar
to the "log" file.  But not quite.  All List messages give the List
address in the "log" file.  Not the actual From: address.  And as well, I
don't wish to collect anything BUT the addresses.

Please e-mail or CC: any advice.