SAP offers an add-on for SC commitments as a consulting solution, my current client is using it.
Technically it uses PReqs in ECC for blocking the budget before the PO is created.
It seems that the screenshots above show code from this solution, as I recognize some technical names. Not sure about the legal background for posting this here.
I guess you can contact SAP via SMP or your sales rep about it. It will likely cost some $$$ though.
Thomas