Shipment cost document flow to COPA

Hello Experts ,

   Scenario:-

                    Sales Order on external customer ->Delivery->Shipment-> Shipment cost -> Auto Service Entry Sheet -> PO-> Bill to the Vendor

                    Bill to the external Customer  --> along with accointg , COPA document gets generated

                   While Creating the Shipment cost document , we specfiy a frieght condition type  which captures the Freight and this Freight

                   condition type is mapped to COPA

                    While Saving the Shipment cost document Service entry sheet gets created and a Accouting entry is posted to capture the direct fright

                    Direct freight GL - DR and

                    GR/IR Credit

                   
                   Finally when the external customer is billed , along with all the characteristics this the Frieght Value also flows to COPA.

                   In case if the vendor has provided a incorrect Freight , we have to cancel the shipment cost document to rebook the freight ,
                   system cancels  the service entry sheet etc... fine  but we don't touch the billing docment that was billled to the customer

                   hence  we have a mismatch cause  the freight in COPA still has the old value

   Question :- We need to capture the shipment cost document in COPA and whenever we cancel the shipment cost document the COPA document

  should also get reversed , and then while billing to the external customer the freight should not flow to COPA else we will have double entry in COPA

   one in shipment cost and the other while billing to external customer

      We basically want the direct freight flow to COPA during shipment cost and not while billing to the external customer ...

       What are the necessary configs required to acheive this ??? , your help is greatly appreciated !!

      Will reward points for the same

       Looking forward to hear expert comments

Thanks

Aryan