I just took the submit button off my high score screen, I was having too much trouble with the button.
I did it with the Keyboard object.
Event conditions:
Keyboard Return is down
System Trigger Once
In the event, it reads whatever is in the text field. So you would know the next character in the box was a Return Key.
I added the "System trigger once" so it wouldn't submit more than one time.
Is that what you mean, or at least offer an idea?