I'm not overly familiar with how ActiveX controls interface with InfoPath code (if at all). The control creator could probably give you more detail. There might be some way to interface with them, though I suspect not.
All of the built-in controls are NOT accessible via code. They are all auto-updating, etc. It is my understanding that ActiveX controls need to be designed the same way and that they too have no code hookup to work with.
Maybe someone can prove me wrong and give you some other helpful info...