JoergHH
Hi,
You can do this in two ways:
Click on the cinema scene button, which is located over the playback menu, the one on the rightmost. You can change the scene to either Void or Space Station. In both those scenes you will be able to drag the screen to where every you want. and the realignment will work for ceilings in this case. (A bit more explanation: You cannot watch on the ceils in the movie theatre scene because we feel like with concert ground and realistic physical structures in this scene, it is inappropriate to move the scene vertically. But again, you can do this with the other two scenes with no problem. )
You can also try to Lock the screen right in front of your face by clicking the "Lock" button in the "advanced setting" sub-menu on the playback menu. It will automatically switch the movie to Void and stick it in front of your eyes.
Note that these are specific to flat movies, that is, settings will be a bit different for 180/360 movies, but based on your question I assume you are watching a normal movie.
Hope this helps,
Andy