credit note against modifier (discount)

Dear Friends,

We have a requirement in order management as follows:

The invoices against the order should be of the same value as calculated from the unit price in price list

The modifier (Discount) part should go as a credit note to the customer.

e.g.

    

Existing Setup

 

In the current scenario if we have an order line having 5 numbers of item x with a price list having unit price of $12 and Modifier (Discount) as $2

The invoice will be generated for the value $50 = 5x(12-2)

    

Required Setup

If we have an order line having 5 numbers of item x with a price list having unit price of $12 and Modifier (Discount) as $2