<p>If I have a native C++ windows program (i.e. the entry point is WinMain) how do I view output from console functions like std::cout?</p>

Since there's no console window, this is
impossible
difficult. (Learn something new every day - I never knew about the console functions!)
Is it possible for you to replace your output calls?  I will often use TRACE or OutputDebugString to send information to the Visual Studio output window.