Customer Material info display

Dear Guru's

We have an requirement on Customer material info and Customer PO Number

The Customer uses his own material number for the parts sold and this should be displayed in Delivery and Packing list, using this only he recognizes the material , I have maintained Masters in VD51 the same info has to flow in Delivery and packing list.

and he also Maintains different PO Number material wise a scheduling agreement consists different items and each item consists of different PO.

So Kindly suggest me as of how to go about.

Regards

Kiran Nazare