IPFW, Nat and transparent proxy ( on different machines )

[CPD - Equipe deSegurança]

Dear gentleman,


   So far I've been running a FreeBSD 4.7 machine which runs NAT, IPFW and 
Squid , acting like a transparent proxy/cache , NAT box and packet 
filter/firewall.

   Now, the load is getting too heavy, so I'd like to use a second machine 
(with a second WAN link ) as a separate proxy for the HTTP traffic.

   Question is, how can I set up IPFW/NAT to send all the HTTTP ( port 80 
only ) traffic that comes on the internal interface ( 192.160.0.1 ) to the 
new proxy-only machine's internal interface ( 192.168.0.2), and still have 
the rest of the traffic flowing normally through the other gateway, which 
will now run only NAT and IPFW as firewall.

   It's confusing somehow, I hope I managed to be clear enough.

Thanks for any insight,

- Alexandre