I have to implement the following functionality:

In my application I have a pullright menu popped out from a cascade
button in a pulldown menu; the buttons in this pullright menu are a
group of mutually exclusive toggle buttons, that is, it's as if the
pullright menu were a sort of radio box.

to achieve this have I got to act on the RowColumn resources
XmNradioBehaviour and XmNisHomogeneous and XmNentryClass? Is there
something else to do or something better to do?