I recommend you to use aIWnet to run modded lobbies... Because first of all is the console at aIWnet already enabled and pops up after starting "iw4mp.exe" 2nd you won't get banned for hosting a modded lobby and at least 3rd you need the console hack if you are running modded lobbies on steam mw2 and that will get you banned
If you want to force host just start mw2 press CTRL + Tab or open Taskmanager to get back to your desktop. Open the Console (she's running in Background) and type:
into the console, get back to your mw2 and search for a Game.
party_hostmigration 0; party_connecttimeout 1; badhost_endgameifisuck 0