R4981/R42800

i'm looking to see if there is a way to split out the sales order lines at sometime from ship confirm to sales update

Example.

I've got SO 1000 (700lbs) and 2000 (300lbs) both on shipment 3000

shipment 3000 is rated for billable of $1,000

when R4981 runs, it will add a freight line to one of the sales orders for $1,000.

When R42800 executes, it will do some freight allocations(based on percent of weight) on the invoices but doesn't change/add lines to the order sales order.

I'm looking for a way to have sales order freight lines allocated and portrayed on the sales order and NOT lumped together.