If you are trying to play games that block users from outside the base country your ISP's address will give away your country of origin. You might try changing the DNS server by looking at services like DynDNS.
I'm not real sure DNS is going to help you there. Most I believe are just doing a who is on your source IP... and changing your DNS entries aren't really going to help you there unless I'm missing something there.
I think your better bet is to try and find some sorta proxy that might work with the game.