Project Budget to be sent back to Project

Hi Team,

We have a requirement as below:

1. Users will create Requisition with Project details. This Requisition will be then Autocreated to PO.
2. PO will be received
3. PO will be invoiced. However while invoicing the PO users will be invoicing the discounted amount. So, now there will be a difference in PO amount and invoice amount. Since the invoice will be with discounted price, the invoice amount will be less than the PO amount.

We have a requirement that this difference between PO amount and Invoice amount should be sent back to the Project Budget. Can you please assist if this feasible? and what would be the approach to achieve this?