Transparent proxy redirection has been discussed on this list before.
Manuel has said that it is a function he wants to add, but it's not all
that easy to do.  I guess the short answer is no, you can't do that
right now.  I am, however, working on an extension to make m0n0wall
function as a proxy server.  It probably won't be available for beta for
at least another week though.  

-----Original Message-----
From: Gregory W. Mills [mailto:gregory at ohmuffin dot com] 
Sent: Friday, June 04, 2004 8:59 AM
To: 'Jason Crowley'
Subject: RE: [m0n0wall] outgoing proxys

Would like it to reroute traffic through a proxy

Gregory Mills
Founder of oh Muffin!
aim: ex2four7
msn: ex2four7 at hotmail dot com
email: gregory at ohmuffin dot com
http: http://www.ohmuffin.com