Plan Cost update during sales order save

Hi,

While the sales order save, plan cost is getting calculated at background. I want to change that cost. Is there any user exit, BADI availble to do so.

I tried sales order save user exits like MOVE_TO_VBAP, SALES_DOCUMENT_SAVE, SAVE_DOCUMENT_PREPARE but it doesn't works.

Is there any other way to change costing which gets generated during sales order save?

Please reply.