need some heip in screeen enhancement

hi my requirement is to enhance the screen the details for it is

Sales order header ‘Additional Data B’ is on screen SAPMV45A 4002. These screens contain the Include screens SAPMV45A 8309 as user exits.

Application-specific check module are to be included in the Include Program MV45AIZZ

this is the spec what they gave

i dont know how to proceed can any body help

actually i have to create 2 tables 1 table with 1 field

and what ever that table contains must be displayed in that additional data b with check boxes

please help