How to autoapprove a PO when created from PR

How do I set the purchase order to automatically approve if it is created from a purchase requisition?

Process Desired:

1. Requisition is created and submitted for approval

2. Requisition is approved

3. Purchase order is created from requisition

4. Purchase order is submitted and automatically approved regardless of buyer approval levels as long as PO was created from approved requisition.

Thanks for the help!

Kristen