Looks like this thread hasn't come up with the solution *I*
personally was hoping for!

Perhaps if we ask it another way:

The Debugger has a Call Stack dialog box (Ctrl-L) which is useful in
debugging during break mode.
But, are there any Functions that can return the contents of the Call
Stack?

Haven't been able to find any, but if the MS Wizards were able to get
it to PRODUCE the Call Stack Dialog, then they MUST be there!