I guess I am out of luck. In checking online I learn that Macs are not a supported system for this device. (Although it seems to work fine for LibreOffice. I originally purchased this for my Windows 7 machine. I subsequently decided to try a Mac rather than switch to Windows 10).
I went back and tried the combination of the remote with PM on my Windows 7 machine. That didn't work either. But in playing with Windows Explorer, it now looks to me that the remote is transmitting a page-up/page-down signal rather than up-arrow/down-arrow.
OK, this is getting too messy, too quickly. And the bottom line is that I am using an unsupported peripheral on my Mac and then asking Camera Bits whether they can help me make it work. Good luck with that.
But before I go out and buy another remote compatible with my Mac, perhaps I can ask the general community: Has anyone had success in controlling PM with a presentation remote? Has anyone tried?
Kirk: Thanks for your quick response and pushing me towards the straight and narrow. Maybe I'll be revive this topic in the future but hopefully better informed.