Posting actual costs for claim's internal order

Hi Experts

I am working on below scenario:

The vendor has supplied equipment with deviations for project. Client is not intended to charge vendor but plan and implement corrections.

I have generated a claim with unit costing for additional material with generation of internal order. Thus the additional costs are planned using the internal order.

My query is, how to generate purchase requisitions for the materials planned with unit costing in claim. Any method for further processing of procurement functions with reference to claim. The intention is to post the actual costs for the claim internal order.

warm regards

ramSiva