[otrs] PostMaster filter to process a TicketTime Value

Hi, We'd like to be able to have our customers specify a deadline for some e-mail requests. We use TicketFreeTime2 field for that. Is it possible to process an e-mail with a filter so that if a customer sends an e-mail that contains something like: Deadline: 2011-09-09 10:12:00, it sets the X-OTRS-TicketTime2 to 2011-09-09 10:12:00? Thanks, Ugo