Help: How to fill Checkbox field with data from another form

Help: How to fill Checkbox field with data from another form

I'm trying to populate the values of a checkbox field (EstRequest.Send) with data from another form with criteria. My source is team_member[role == "Contractor"].name. The destination form EstRequest has 2 fields: Job & Send I need to be able to check one or more names and send email to each on submit.
Can you please show me how to code this? Many thanks.
Frank