To show you how to mix these two very different languages, there is a video for you to watch.The real meat of the talk starts at around the 7-minute mark. The example simply displays an input image and a processed image - the processing is done using C++.
It is all very easy but it's another reinvention of the wheel. Or is it a return to a simplified wheel? At first there was COM and it was difficult and had lots of problems. Then there was .NET and introspection, which did away with the complexities of COM. Now there is the WinRT component, which is COM reinvented to be as easy to use as a .NET runtime object.
All of this isnt' bad - it's just very strange and, dare I say it, not very logical.