Which exit for MIGO Subcontracting

Dear Abaper,

We were using MB1B t-code for doing subcontracting with reference to PO. We had used a BADI for that.

Now, we have upgraded our system to EHP6.

In EHP6 MB1B is obsolete. And as per SAP we have to use MIGO.

In MIGO we cannot do subcontracting with reference to PO.

In the transaction MIGO this PO reference functionality is not implemented for movement type 541.

There are so many exits available in MIGO,

please tell me which exit to use to do the subcontracting with Movement type 541 for MIGO Transaction.

Thanks and Regards,

Arati.