Adding multiple child records to a parent record

Hi, thankyou for wading in! I have created a form where a new RFQ header record is created and saved. Once saved, on the same form i have a report link to a list of filtered Configuration records which are available to be added. I cannot figure out a way to pick up the current RFQ reference and allow only this to be selected in the [Related RFQ] field on the Configuration record.