I have a lot of purchased movies in itunes, vudu and so on. I have used other apps which include deep links to movies on the above services, so if I click the Matrix it opens in itunes and so on.
As a workaround, I have added a 3-second video as a movie in my Channels Library which tells me which store I purchased the movie from (not all are Movies Anywhere).
What I would like as a feature is the ability to add a link to a purchased movie in an external store, the movie would appear in the Library section of the app in the Channels App amongst the recorded content and any ripped movies I have also imported. The Watch button would open the link, and therefore the relevant app and I would be able to play the movie.