I've got no idea how your ISP would be set up with firewalls etc.
I've never used a proxy but have a look at the thread below, it has a few links. You could also use the forum search to look for proxy or proxies & see what other threads turn up.
Some other forum members might have a few more clues, as well.

http://www.gnutellaforums.com/showpo...52&postcount=2