Screen layout for Network component

Hi ,

I have a new requirement where while creating a PR from a network activity in the Purchasing tab "Vendor Material No " should come as a feild but as of now its not coming. When we create PR through ME53N "Vendor Materail No" feild is coming.

I checked the screen layout for networks but this feild is not present there,

Can anyone help me to find ,how I can bring the "Vendor Material No" feild in the Purchasing tab of Network component.

Thanks.

Neel.