Generating a Stock Transfer Reservation (Not Stock Transport Order) through MRP

Hi,

I would like to achieve the following, using the Stock Transfer Reservations (Reservation created with Mvt 301 against another plant) using MRP.

Plant A holds stock for other plants. Now Plant B now has a requirement for stock. When MRP runs for Plant B, I would like the system to create a Stock Transfer Reservation (Not Stock Transport Order) against Plant A for that stock. Should Plant A not have sufficient stock, the normal external requirement is created for stock to be procured.

Now I am not sure that if it is possible that when the Planned Order is generated, that it can be converted to a Stock Transfer Reservation instead of a Stock Transport Order. I have tried to configure the usage of Special Procurement Type 45, but not sure how it works or how I can get it to work.

I am sure somehow it is possible, but getting to configure it correctly is another story on its own.