I am wondering if it is possible to have fields auto-populate for a contact within a custom created module.  So I have created a custom module called "Weigh-ins".  I am trying to figure out the best solution of calculating the total weight loss since the initial weigh in but there is no way to create a formula field that grabs a value from somewhere else and uses it.  Wondering if not possible in CRM and maybe Zoho creator might be a better route.

Please help!

Thanks!