Trying to create a simple coop, help

[addman]

Ok, so I have this nice little offline mission I made and now I want it to be a coop mission that I can host. I put a blue spawn point on the airfield where I am/we are supposed to take off from, start a server and load the mission but the spawn point isn't in the briefing room and no nationality flag to choose from. Of course I've searched the forums before asking this but haven't found any solution, plz help.