Proxy that change my port

[Tjosan]

Hi..

I´m in a network were lots of ports are blocked... all above 5000 i think..
Lets say i want to play a game online.. is it possible to use a proxy outside my network so i may play the game?

What the proxy must do is to change the port number to a low value between me and the proxy comp...

All computers are connected to Internet :)

Hope you understand the question, i´m not that good to explain it in english :/

Peter