How to use XUnit with Visual studio to unit test code running in a remote process

We are writing plugins for the Solidworks CAD system. Writing an addin involves compiling a DLL, registering it and then starting solidworks. Code in the dll can be configured to execute as soon as solidworks starts.

What I would like to do is craft a special DLL so that it runs a series of unit tests or a single unit test from visual studio and reports the results back to visual studio in the standard way.

We are happy to use either the standard visual studio test or resharper test system.

Is it possible to write an extension to the unit test system to achieve this. If so how difficult is this to achieve. Perhaps there are extensions that already do something similar for other plugin type environments that need testing.