title: Pass managed IntPtr window handle parameter to C++ COM dll function expecting HWND
body: <p>I'm creating a COM object that needs a HWND for a window handle coming from WPF (HwndHost). All I have is IntPtr which comes from HwndHost.Handle.</p>
  
  <p>How do I pass this correctly to my COM object? I'm not using P/Invoke.</p>
  
  <p>I don't care whether the conversion happens in .NET or C++, but prefer whichever is best practice.</p>