Put SmartShape Buttons in a Master Slide’s Fluid Box – How to refer to them in an Advanced Action?

Have created a custom Playback control using six SmartShape buttons used to control Play/Pause, Sound, forward, backward, CC, and TOC.  All this to control when a user is able to go forward yet still be able to review material already viewed.

What seems ideal for  the students learning, is to see the forward button but not be able to advance until the slide has completed and that same forward button enabled when the slide has already been reviewed. Also to rewind within the slide to review material is important without having to restart the slide completely.