Custom PO Requisition Account generator

Dear All,

    We would like to change Requestion Budge Account Code combination based on the DFF captured at Requisition line level.

    In Requisition line DFF we are capturing Project segment and this has to be updated in Budget code combination.

    For example:

    The default Budget Account is 001-801-20250-213-000-000   i.e...Company-Location-Account-Department-Project-Future.

    We enter at Requestion line DFF project as 001 or any other project segment.

    As 001 is the project the code combination has to be 001-801-20250-213-001-000 i.e. Project value from 000 to getting updated with 001.

    Please advice what all changes need to be made to achieve this solution.