[Exim] rbl-check for forwarded spam

I'm thinking of trying to use Bjarni Einarsson's rbl-check system
(http://bre.klaki.net/programs/spam/rbl-check.pl.txt) that checks for
blacklisted sites in Received: headers. Since it's in perl, I thought
I might be able to run it with the embedded perl facility.

Has anyone tried this or done anything else in exim for dealing with
forwarded spam? The regular blacklist facilities only work when the
blacklisted site is the one contacting you directly.

Thanks.

                Ken