How to re-route shipments in batch after Route Code changed in Customer Master

Hi,

Client migrated customer master records and sales orders with one default Route Code. All migrated sales orders have shipments with a generic route with the same carrier. Now the customer master records have been updated with real Route Codes that reflect the geographic areas where the customers are. I am looking for a batch update that will populate the changed Route Codes from the Customer Master onto the open sales orders and then onto the related shipments so that they are re-routed to the real routes and carriers.

I have tested R42950, R42995 and R42990 but none of these jobs have changed the Route Code on the sales orders and shipments. We manually have to change the Route Code on the sales order header and detail and on the shipment to get it to re-route. It is not feasible to update all orders manually.