I was properly looking for a simple task just to start studying how to develop vuonodes... it was really easy as dot and cross product primitives are already developed in SDK. Here they are. Just decompress and drop to your User Modules Folder.
Here is reported range is 60cm; but to my experience this wasn't a huge limit, providing the correct installation setup. My setup expected the user pointed with its finger towards a huge mapped projection. If this is your situation also, vuo Leap nodes is the best out-of-the-box solution as you get a xy position of the user pointed position. Last Vuo release supports Kinect2, but I see this less useful for this specific task.