I would strongly encourage you to use the class TControlBar instead.
We have an example in the tutorials. TControlBar is independent
of Motif or Windows/NT and you do not need to know anything about
the underlying Motif data structures/widgets such as the Widget type
itself.
If you want to use TMotifControlBar (internally used by TControlBar
on X/Windows systems), you can look at the source of this class
now available on the Web, but you will need quickly access to
the Motif users guide (eg X and Motif Quick Reference Guide
by Randi J.Rost, Digital Press).
Rene Brun