Little bit of coding help

[Blumy]

I use the hack Forum Tournaments & Ladders for 3.7.x for Xbox 360 game ladders. Can anyone help me code a way so when people challenge each other three maps and gametypes are randomly generated out of a list and then posted within the challenge? I want to use it for Halo 3, Gears of War 2, and Call of Duty. Any help or advice would be greatly appreciated.