Oh! I know exactly what you mean, your talking about what the program hamachi does. Where it basically connects to a virtual connection between you and another PC. One of the PC's basically creates a network , then a person with hamachi connects to your network so you can share files or even connect to each others PC's over the internet.
I've done this with the program hamachi and it's worked out pretty well for me, my friend and I(me in las vegas and he in virginia) run CNC 3 full resolution and roughly 5 other bot players without any considerable lag. There can be drops within the game and it can be frustrating seeing we are both on wireless connections using hamachi. There is something called tunneling but Iam not quite educated on the technique, it basically allows a better connection between pc's using programs like hamachi.