Building a MVVM 3D Editor Application -> Getting Mouse Position?

[Steve The Plant]

Hi, In my 3d editor application, I want to be able to click on and move a scene's entities (meshes, lights, cameras, etc). To do that, I imagine that I need to get the current mouse position relative to my Direct3d view and somehow give it to my ViewModel. How would I go about doing that, considering that my app is built with the Model-View-ViewModel pattern? Thanks!