Can anyone give me some information, please ...

I need (probably) to write one or more new Motif widgets on the HP-UX
platform. Do I need the Motif private header files and source,
or can I make do with the public headers that are provided?
"Motif" includes Xt in this context.

One widget is a multi-column list (which lots of people have
already written, I am sure), and would therefore be probably be
a subclass of List rather than something simple like an Xt class.
Is this more difficult (in principle, not lines of code)?

Alternatively, if anyone has a multi-column list widget they
could sell me, this might save me from having to write one!
Does it by any chance exist in Motif 1.2 already (I do not
yet have the spec)?

Answers appreciated,

Nicholas.