How To Pass variables to a Server Map Gamemode from a Client Menu

Hi, I am building a dedicated server for my multiplayer shooter game and want to pass the maxNumPlayers variable and levelMap variable from the menu to the lobbymap gamemode. The lobbymap is the server map where players join the game and from the lobby if the players loggedin is equal to maxNumPlayers set by the game host, the gamemode will take the players to the appropriate gamemap. So my problem is Im unable to pass the variable maxNumPlayers and levelmap from the menu to the server map’s gamemode. Any help will be appredicated.