[exim] How to not deliver an email with certain keywords in …

exim4 and not running spamasassin

I've seen some close examples of what I want but so far the keywords are in the config file, (if
$header_subject: contains " ") and the like.

How can I have an external file of keywords (regular expressions would be nice) and what changes to
the exim4 setup so that any mail with any of the keywords is not delivered. It seems the changes
would go in to /etc/exim4/exim4.conf.template but I cant find out how to do it.
--
George Dau
I.T. Support Officer
EMail: itcoord@???
Phone: 040 7150 668
Mount Isa - Rodeo Capital of Australia