Please pardon me if this answer is too basic, but...
You can read any array of strings into a property node for the standard Listbox control. Right click on the control>>Create>>Property Node. On the new Property Node, right click>>Properties>>Item Names, then right click>>Change all to write. Now you can take an array of strings and feed it into the property node. When run, those strings will appear in the list box as selection possiblities.
Of course, this glosses over how to get the values OUT of the DLL in the first place, but I'm afraid I can't help you there :(.
