Yes now is posible with the program
hamachi. This program is free.
http://www.hamachi.cc/
Just install the program and make a server in to the program. Then tell to a friend to join in the server after that make LAN game server. Your friend will see the server in the LAN tab of the game that you want to play.
While you play the program must be active. If you don't understand somethink just write here and I will help.
But don't forget to configurate your firewall.