Ability to auto-create a PO off of a PO

Our Procurement group would like to have the ability to have a PO automatically generate off of an initial PO.  As an example, they purchase a truckload of broccoli and enter a PO for the broccoli (inventory item).  At the time of entering this PO, they also need a freight PO with the trucker (different supplier) for the delivery cost (expense).  They would like to be able to (in some manner or based on some criteria) have the freight PO generate automatically when the initial broccoli PO is created, rather than creating the PO separately from scratch.  We do not