Can you be more specific on why you would need the enter key restricted ?
EXFMT = WRITE followed by a READ
So if you do just a WRITE – you are basically displaying the record format without accepting any input.
If the user presses any key, I suppose you could retrieve the status (Exception/Error Codes) from the INFDS to determine how you want to proceed next.
I have not done this before, so not sure if this will work or not.