Ummm use this command line (Don't know if this one works) set fs_game mods/(mod you want); set sv_pb 0; set sv_dedicated 1; set sv_maprotation (maprotation u prefer); set rcon_password (password and i don't know if it should be rcon_password or rcon Password just try it out so here it is:
set fs_game mods/zombies 1.52;set sv_pb 0; set sv_dedicated 1; set sv_maprotation mp_strike; set rcon_password poopies