Have you tried meetupBot yet? I hear it can do some magical things 
Don't talk to me about meetup bots!
I used to host meetups in the past, but meetup bots kept swooping in and stealing my guests for $1L. The good ones sent them back after I PMed them, but I still ended up losing a load
Last I heard the people who own the meetup bots were selling my guests on SLX as 'meetup in a box'.
Vale