You can use OnMouseEnter and OnMouseLeave:
DesktopX.Object("Target").state = "state1"
DesktopX.Object("Target").state = "Default"
You would have to do this for each button, making sure to change "state1" to whatever state is supposed to be shown on mouse enter. "Default" state should be changed to whatever state you want showing when no buttons are moused over.
DX Scripting Reference