Project distribution amount from PO

Hi,

I am working on a custom report to fetch the following information relating to a project-task combination:

Project Number | Task Number | Sum of all Purchase Order amount (open/closed but not cancelled) | Sum of all AP Invoices (against the POs) | Sum of all Payments (against the AP Invoices)

I am trying to fetch these from the 'ENCUMBERED_AMOUNT' column from the 'PO_DISTRIBUTIONS_ALL' table for that project-task combination. But not able to get the proper value, as this filed is based on the reservation made in the GL budgets.

Can someone guide me how to fetch this distribution amount?