How evaluate clicked commandbuttons on form

I have a form with a group of three commandbuttons: if a user clicks just one of the commandbuttonvalues is True, the other two are false. While the form is still open I have to evaluate which button has been clicked, so a sub procedure can be started. I have two questions:
1. I managed evaluate the clicked button indirectly by declaring three Public variables, but I think that that is a very poor method. Is there a better and more robust way to do that?
2. I want to change the color of the caption of the clicked button, but my attempts sofar failed.
See my attachment.
Can someone help me out? Thanks very much in advance.