Yes you can go ahead as you mentioned.
Configuration required as below:
1.Define new Z item category(ZREN) as you mentioned( for that billing relevance is blank).
2. In VOV4 assign this z item category in manual item category column
Example : RE+NORM+Usage+REN+ZREN
So that when ever you are creating return order system by default determine REN that you can change it to ZREN.
3. Maintain copy control in VTLA between RE and ZREN
Process:
- VA01(RE) manually change the item category from REN to ZREN
- VL01N( Return delivery) goods receipt.
If the customer wants goods in return for the missing order qty then you can go with subseq free of charge delivery i assume you know this standard process.
thanks,
Srinu.