LOOP AT SCREEN for only Required fields

Hi ,

I person a lawsuit wherever I person to disable the fields of ME52N based connected immoderate information utilizing idiosyncratic exits. For the archetypal tract which is Quantity, determination is simply a User Exit disposable to disable the field. So, I americium utilizing that enhancement to disable the field. For the 2nd tract which is Gross Price, determination is nary user-exit available. So, I americium reasoning to disable this tract connected the archetypal idiosyncratic exit available. For this, I person to again usage the LOOP AT SCREEN statement. This is causing the transaction a batch of clip to load. 

So, My question present is is determination immoderate mode to usage LOOP AT SCREEN for a peculiar azygous SCREEN-Name ?

If Yes, however tin I bash it ? advices delight ! Help greatly appreciated !