This can be done in a button but the steps involved are too many to explain here, unless you are really good at Quick Base as i can't take the timer to explain every click and syntax. This would probably take me an hour to setup and demo to you, so if you want to pursue it contact me via the info in my website
QuickBaseCoach.com.
Basically I make a self populating table of users, key field user, called User focus. The user clicks a button and their userid is edited or added to include the focus batch number for the record that you are sitting on. Then the button's next step is to import the records with the blank batch numbers into themselves using API_RunImport and update just the [Related Batch] with the user focus batch#. Then re-display the batch record so the user can see the child records are now attached.