How can I use add record to create multiple records from one?

I can use add record to create one additional record, but not for the multiple that I want.

I am using forms to submit orders for advertising, so I need the same form to apply to various dates in order for a report for a given date to be accurate.

The solution, I though, was to have a field assign a number of "runs" or "insertions" of a given advertisement, then the function could create copies of that same record, with .addWeek(2) for the date field, according to the number of times in that field. But I can't figure it out.

Anyone know how to accomplish this?