I've just tried to disassemble BaseCamp.exe with IDA and .NET Reflector. Both of them can't find SQL request strings in the disassembled code, which is strange as they are clearly visible in BaseCamp.exe. But they are able to find some other strings. One more strange thing is that the SQL request strings are one-byte-per-char while the other strings are two-bytes-per-char.
So.. I just don't understand.. Will return to it tomorrow.
UPD
In fact those SQL request strings are used by a few native functions (compiled into x86 instructions). Gonna figure out how managed functions call native functions in .NET.
Or maybe... GPSFranz, are you absolutely sure that those coordinates are different from coordinates used in other files like gpx, etc? Maybe it's worth trying creating a custom GPX file and loading it into BaseCamp and checking of it fits the named trail?