Default Warehouse based on Ship to Customer Site and Item

Content

Hi,

 We have a requirement to Default the warehouse based on Ship To Customer Site and Item combination? Is it possible to achieve this via OM extension or Pre Transformation Rule.

IF Order type = Regular

And

Warehouse is Blank

And

Item = 123456789

And

Custom ship to = Walmare Distribution Center A

Then

Do

Set Warehouse = 001