As far as I can tell, the faction menu in the reference window doesn't add player created factions to itself, so I'm assuming a script would be the only way to do this. But, the CK wiki site doesn't have a clear example of using the setfactionowner() object reference script, so I'm having trouble... Beyond that, the Papyrus tutorials primarily focus on events, and since this isn't quest based (at the moment), that doesn't help me.