Sendmail question

[Steve Shockley]

I have an OpenBSD machine that will handle outbound mail using Sendmail. 
I'd like Sendmail to scan the messages, and any messages with a certain 
word in the subject will be sent to a specific server instead of the 
Internet.  I've figured out how to *block* messages based on the subject 
using LOCAL_RULESETS, but not how to re-route them.  I'd rather not 
rewrite the From: address, but I can if I must.  Can someone give me a 
pointer on how to do this?  Thanks.