The mach screen designer will let you add any button to any screen. If the button is on one of the Newfangled wizard screens it will be locked to code editing.
If it is to show the H number you dont want a button, you want a DRO.
There are two screen designers, Machscreen is my favorite. Get it from http://www.kd-dietz.com/klausphp/pages/eng/machscreen/description/ms_description.html