For background of the Left, Right, Top windows choose Edit(Edit of the view window not the main program edit menu)/Configure then click the Back tab and add your movie there. It will animate automatically.
Otherwise use a background object or a plane and put your movie in a material (color or luminance channel) and put the material on the BG Object/Plane. To get it to animate as you scrub the timeline you have to go into the Illumination tab of the material and check off Animate Preview.