Modification in transaction ME2xN - need help

Hi,

I have to make a modification in transaction ME21/22/23N.

I want that in the tab of the acount assignment of a position (purchase order) that there is a new field that should only display data based on order (displayed in the same tab) - it is no input necessary...

But I cant really find the dynpro that contains this data-fields so that I can add the additional field...

Can you help me?

Thanks a lot!

Kind regards

Markus