Okay, I put "23" in the LOC box for runway 23 and it displays "2NC5" above without an error message. I'm not sure what that means, but the aircraft still can't seem to capture the localizer (yes, they are on a 30 degree or less intercept heading).
For 18C, it shows "KCLT" at the top. The GS seems to work as well. However, the lateral path for the runway is off. The plane flies in between runway 18C and 18L instead of on the centerline, so the coordinates may need some tweaking.
I also got a "no elevation data for airport" error when typing "GS" for runway 23. So it seems like with run