How to use Hamachi to enable play on EA Command and Conquer Generals ?

Hi all, have been having massive problems trying to play against my son at Generals with our laptops on a wireless netowrk, so instead of giving up, I looked on the interweb, and found that Hamachi helped solve the problem.  I have downloaded it and installed it, then opened it, but not sure what to do next, can any of you help please?  I would make a donation of 20usd to you or this forum, if you can make a father and son very happy at this time of year.
Chris.