ipfilter and transparent proxy through squid

[Gabriele Bulfon]

Hello,
how can I achieve the same as stated in the link below, but using ipfilter?
http://www.cyberciti.biz/tips/linux-setup-transparent-proxy-squid-howto.html
thanx for any help
Gabriele.
Gabriele Bulfon - Sonicle S.r.l.
Tel +39 028246016 Int. 30 - Fax +39 028243880
via Enrico Fermi 44 - 20090, Assago - Milano - Italy
http://www.sonicle.com