Batch number in Display mode only..

Dear all,

While creating sales order--we want to keep the field batch number derived --should be in display mode only..

I tried with SHD0--But not working(after activation of this as standard variant)(both the screens at 4451 and 4490 too)

I tried with SE51--but problem --currently we dont have the access key with us..

Also what is 4001/4003 screen number at the F1 help--technical settings.(this screen numbers are not giving me an option of output only)

Here i have to go with exit level only or what --Please Guide??

If so --can i use the exit---USEREXIT_FIELD_MODIFICATION in MV45AFZZ---Please suggest.

See the screen shots for more clarity..

Phanikumar