Different production plant in a Planned Order

Hello Gurus,

Is there a way one can automate the prodcution plant to be populated different from the planning plant.

The Production plant is getting populates as 4000 say by default in the Hdr of the planned order.

We want to automatically populate it with 4001.

The reason is to get the BOMs from 4000 into 4001 planned order without cretaing the BOMs in 4001.

Please advise.

Thanks!
AP.