Parag,
You need to check with the business regarding the business process side, what if for an order, returns keep coming for months, in other words order has 10 items which were delivered to the customer in two deliveries, first return order was created this month and the second return order was created after 3 months. When will the company make the SDF order?
Your need is that system should not allow a new SDF order for items of the same order, for which a SDF order has already been created.
Technically, as Naveen commented this cannot be achieved through standard SAP SD. You need to go for enhancement.
Probably the design could be -
1. routine field DataT in copy control, header level, VTAA should combine taking into consideration original order no. (and not reference RE order no.). Here you need to develop a custom routine, configuration - assign it in the copy control configuration
2. A custom table which will not the original order no. for which SDF order has already been created and system will not allow SDF order creation for an original order no. on this z table. The logic for validation can be put in the routine above.
TW
Message was edited by: TW Typewriter minor changes to point1