Transmitting PO using XML

Hi,

I am working on implementing SRM 4.0. I am new to it.

One of our reqirements is to send PO using XML, to some of the vendors. How do we achieve this? Do we need to make changes in configuration? Do we need to implement any BADI's? Please help as I do not have any idea whatsoever on how to achieve this.

Thanks,

John