BDC Help

Dear friends,

This is my req:

I have a Delivery schedule with three line items as below

Matnr qty

CYLINDER 500

CRANKASE 400

hammer 300

and i have a billing document

cylinder 100

hammer 50

so i want ot execute a bdc for tcode vl31n for shipping the billing document.

in the transaction it must select only the first and thrid item (iems in billing doc)and update the shipping qty

and delete the second item which is not in the billing document.

Can any body help me how do go for this.