[Cubie]

I've been fighting with what sounds to be simple thing but I cant figure it out.

I'd like to select a random player from all the players that have:
Gamemode[playerid] = 1.
or
Gamemode[playerid] = 3.
Etc. Etc.

I.e:

Playerid 1,5,7,9 have Gamemode[playerid] = 1, so I want a random player from that group.
It's probably pretty easy but I need someone to push me into the right direction.
Thanks.