Hello, i need help to pull data from one field into another.

Module - opportunity

1.So in example below - attached = Pull data from

- Builds subform - if Quote/Estimate/Invoice check box is checked (add to) or unchecked (Remove from) the products section, just the product_lookup..

2.See example below - attached = add to products

- enter or remove products base on Quote/Estimate/Invoice box being checked or unchecked, just product_lookup from the builds subform

basically we have an api dumping data into our custom subform "Builds", i need just the product_lookup to come down to products section on the same module so i can build Quotes and such easier and with just the products the customer has selected which is why we have the Quote/Esimate/Invoice checkbox...