User Exit/ BADI for Me23n

Dear friends,

In a purchase order, in the item detail there is "invoice" tab. for the item category B "Invoicing plan" push button appears in the invoice tab. my requirement is if we click on this button the GR non-valuated check box in the "Delivery" tab of item detailsl should be checked. Is there any user exit/badi exists to accomplish? Please advise.