I know how to use the in-program rate function to slow down preview speed but when ever i save the new video clip, it still has default playback speed. How do I change the speed of the playback, (eg, slow motion, fast motion) and be able to render a new video clip with the new playback speed? Also of less importance: is there a way of having some sections of the video clip have different playback speeds than others?

thanks for your help