Perfect layout John:
I did exactly as you had layed out and attached is a copy of a working vi I made in 8.2. If anyone else wanted to get all running windows and their handles take a look at my vi.
I was using similar routine to EnumWindows and use first and last hwnds to complete search and only enum windows with names.
Do not forget to close handles after you done using them...
While we're on the subject of HWNDs and LabVIEW. I figured I would share a nice little reuse VI that gives the HWND of a LabVIEW front panel window.
I realize people have been doing this for a while but they generally do it using the front panel window title, and then use that to get the HWND. A more robust way is to use the Private Method Native Window.
This VI does have a private method (and an optional depracated method) so causion should be used, and use this at your own risk, understanding functionality of this property may change without notice on other LabVIEW versions.