After digging deeper into the GPX Sonar forums, I discovered this tip from another post and it works:
Run file explorer ( start/programs/file explorer )
Select my device, then tap the program files, then gpxsonar folders. (You should see the config folder in there, along with Docs and Export)
If it's not there, tap and hold in the blank area of the window, and select new folder. Then rename the new folder to Config.
Now I just have to try to remember what trade items I put in which caches over the weekend
Thanks for your input.