InfoPath Dev

I am trying to figure out how to allow users to populate a repeating table with information and then to have them select certain rows in that table and have it populate another repeating table.  The form has a database backend, so the second repeating table is from the database.  So, basically I have a repeating table whereas individuals participate in an event, but some of those individuals need to be billed while others do not.  Those that need to be billed get selected and fed into the billing database table.  Hope that makes sense.  I do not use Qdabra qRules and do not have the resources to use them so I have to do this through some other means.  Any help would be awesome.  Thank you. 

I think I would add a trigger to my SQL table to create the rows in the billing database table. InfoPath doesn't have a way for you to insert rows via rules, so you need code... But if you have access to the SQL tables, a trigger may do what you need.