There are a number of ways I think you could, You could setp it using a User Defined M-code (probably the simplest way), trigger it with another hal pin such as motion.digital-out-NN.
One really nice thing about glade vs pyvcp, is you can make the buttons look like big ordinary buttons, rather than just little tiny check mark dots.
But it does seem to lack that hal changepin part, that you have to add manually with the python file when using glade.
