Ok, so I have tested and confirmed that the following method works for forcing the use of the private L4D2 servers on Janus:


mm_dedicated_force_servers "209.98.155.113:27023,209.98.155.113:27024"

Note that you MUST use IP addresses and NOT hostnames in that directive. You can either enter that in the console or put that in your autoexec.cfg file located at

C:\path\to\Steam\steamapps\common\left 4 dead 2\left4dead2\cfg\autoexec.cfg


Don't forget, you can see the current listings of who is on what server at:


http://janus.splitstreams.com/l4d_servers.php