Thank you Erich! It seems to be working using an ExtInt_LDD. I won't get hardware for a couple of weeks to actually test it, but I do have an "_OnInterrupt" event in my events.c now, so I can continue coding.
Just FYI, the tutorial was written for CW 10.4; in 10.6, there is no "Interrupts" section for the Init_GPIO component, so I couldn't figure out how to use that, even though the tutorial says that Init_GPIO is preferred when one needs to set those values. I expect I can write directly to the applicable registers (when I figure out what they are) to get the correct settings for the pull-resistor, etc.
Thanks again.