Forcing Server Spawn Lists

So I’ve been searching the internet, and going through my files over and over again, yet I still can’t find the answer. What I am trying to do is force the user to use the spawn-lists set in the servers settings folder. I cannot find the code that populates the spawnlists according to the players spawnlists. I want them to have their custom spawnlists, but at the same time have spawnlists I have created to their benefit. Any help?