Procurement Priority in SNP Heuristics

We have a scenario where Returned Goods are stored centrally in a warehouse. My client interested in to first look into Returned Warehouse before creating Planned orders or purchase reqs. In other words, DC should first have stock transfer order to bring over whatever is available as returned goods from Returned Warehouse and then create the balance quantity against the forecast at DC.

I had tried giving a higher priority at T-Lane for Returned Warehouse, but SNP Heuristics then create all the subsequent supply elements from Returned Warehouse for the same product rather than creating orders on a manufacturing plant after consuming stock at Returned Warehouse. If I do make procurement periority same for both manufacturing and Returned Warehouse then Heuristics continually create orders on plant and never make a stock transfer to DC for Reutrned Warehouses' inventory.

I was thinking to first run SNP heuristics just between DC and Returned Warehouse and transfer all the available stocks to DC and later run SNP heuristics again between DC and a Plant to create orders for the balance requirements. But this is not working eithe because heuristics continually create supply elements from Returned Warehouse for the whole planning horizon.

Any help appreciated.

CA