Quintin,
Where did you find that example program? I'm not seeing it in my copy of LabVIEW and I didn't find it in a quick search on the web. Also, I'm not sure what your question is about with respect to that example. You mention that you're confused about how the waveform handles are indexed, but what confuses you about that?
So let me know where you're seeing that example and specifically what your questions is and I'll see if I can help you clear things up some. Until then, have a great day.
Tyler S.