If I understand you correctly, you want to programmatically, at run time, change "Item Names" at a single place in your program and have all instances of the control typedef changed at the same time?
I am afraid it is not possible. Using a strict type, the "Item Names" attribute is not available (LV5.1) or the property is read-only (LV6). In LV6 you can write the "Item Names" property only if you use a reference to the typedef control on its control VI. Even then, the changes made programmatically to the strict type are not propagated to instances in memory until the VIs come idle and a manual change enables the "Apply Changes" menu item.
The best hint I can give is to write "Item Names" for every instance of the Listbox control whenever there is a chang
e.