Hamachi is a crude VPN method (a way of making local networks over public ones) and it dodges issues with dynamic IP addresses by having a central server (think something like MSN).
I am guessing the OP runs a copy of pokemon on his machine (probably via an emulator like vbalink or one of the ones that has the same functionality) but lacks people nearby to play with and so made this post (unless there was a PC pokemon game with local network play since last time I checked).
@popcaan welcome to the forums, such things are entirely possible here but you will need to explain yourself a bit better if you want people to join in.