You must declare std::ofstream out; which is required for the logger. You'll get unresolved symbols if you don't have it.
You also need to call out = SetupLog(GetLogPathAsCurrentDllDotLog()); somewhere before using LOG("").

If you want to proxy a DLL you need:

std::ofstream out; // Required for the logger. You'll get unresolved symbols if you don't have it.
bool          logSetup = false;

BOOL APIENTRY DllMain(const HMODULE hModule, const DWORD ulReasonForCall, const LPVOID lpReserved) {
    if (!logSetup) {
        LOG("Initializing.");
        out      = SetupLog(GetLogPathAsCurrentDllDotLog());
        logSetup = true;
    }

    VersionDllProxy proxy;
    return BaseDllMain(hModule, ulReasonForCall, lpReserved, proxy);
}

void DoInjection() { // Essentially the main entry point.
    // TODO: Stuff.
}

And import proxy-router.h in your pch.h along with including this pch.h.

If you want to override a different DLL use the extractor to dump the pragmas and use that instead of proxy-router.h.
ALso replace VersionDllProxy with your own implementation that targets your new DLL.