Greetings, queenjane and others!
You can have a thread running anyway you want, but I'd like to suggest a weekly check-in thread just to keep the thread from getting too long. You could call the thread "Weekly check in, 70 to lose, <and Monday's date each week>".
You could also have this thread in the Support Groups area if you wanted. It would go under Miscellaneous Groups. Whatever you like!
Jay