userexit for update RESB when save Purchase Orders

Hello;

     When I create a purchase order using Tcode "ME21N", if i choose the item cat. as “L”, which means subcontracting.

     The sub items coming form the item's BOM  will be saved in transparent table "RESB",;

     Is it possible to update the information to be saved into RESB when saving the purchase order? Such as quality and batch.

     I have checked this link: User exit for component data in ME21n/ME22n | SCN

     I set some break points in the programs "MM06EFLB_MDPM_MAINTAIN" and "EXIT_SAPMM06E_012", which are mentioned in the link.

      But when I saved a purchase order, the program would not stop at the break points.

    Best Regards!