It is not possible to load a custom logger with an external path for example:
WinUint.exe -l c:\customlogger.dll:out.txt sometest.dll
The problem is the handling of the ':' in the path in ExternalLogger.cpp line 62:
const wchar_t* delimiterPosition = wcschr(reference, L':');
This line splits of only 'c' but not the whole path.