I'm not totally sure I understand what or why you want to do this but here is how you would enable and and disable the animations on a scene director track.
Instead of turning animation controllers on/off I'm enabling and disabling tracks in the scene director. So if my script disables track2 in the scene director then anything on that track won't work until the track is enabled again. See this image I've attached.
Here's the script:
dim dir as xpSceneDirector
dim track2 as xpSceneDirectorTrack
Scene.GetSceneDirectorByName("SceneDirector1", dir)
dir.GetTrackByName("Track2", track2)
track2.enabled = false
#XPression