ok first up u need the unlimited spawn trainer posted/created by iownagexD refer here to get it.
After u have it, start combat arms they way you are suposed to with the unlimited spawns hack.
and go to an elite SnD room, as that is the only game mode i have tested this with.
Go in and turn on the unlimted spawn, press the f9 b utton a few times(2-3), then press the f10 button a few times(2-3), after that just play normaly or do whatever u want, because when the elite kicks u, it wqill do as normal and u end up in the ch lobby, but the difference is u can come right back in the room.
If u didnt know this before, then pls feel free to +rep/ thnx me.. AND iownagexD because without him and his unlimited spawn hack this would be impossible