Subcontracting Purchase Order from ECC sent to APO creates a Plnd Order

Subcontracting Purchase Order from ECC sent to APO creates a Plnd Order with the same Purchase Order# in APO.

We want to influence the source of supply for this internally APO created planned order.

For this, I would like to know what user exit can be used, I have already looked at

(1) BADI: SOURCE DETERMINATION

(2) CIF INBOUND EXTERNAL PROCUREMENT on APO side.

Any other user exits or has someone worked on this scenario.

Thanks

Kumar