You can password protect your server and invite only people you trust. It creates a LAN between you and anyone in your server (in my case, some of my friends).
If you don’t know, Hamachi is a virtual private network program but it’s real easy to use. I ran into a problem a while back where me and my friend wanted to play AOE III over Hamachi. How to: Play Age of Empires III over Hamachi/LAN
