Just post in the thread and say you wanna join...as far as I know, nobody does background checks or demands specific criteria, lol...
Earlier in the year, I planned to stretch until Christmas, and I thought having an accountability partner would lessen the chances of me falling off so I just started a thread stating that I was stretching until Christmas and that I wanted a buddy. A LOT of people responded so we just made it a club...and now we have the Christmas Stretch Club of about 30 members which will be dismantled in a few weeks.
Anyhow, it's really simple..if there's something specific you want that doesn't exist, start it. Otherwise, post in the appropriate thread explaining your situation and join!
HTH...
{DI}