ActivePresenter is quite like Powerpoint in one sense but it does have a screen recorder so that you could record desktop activity and save it as a video for uploading to the Helix Media Library.  Having recorded your screencast, ActivePresenter goes straight into its own editor and it has a good range of functions including Closed Captions, annotations, zoom-n-pan, as well as the basic video editing functions.  Did I mention it's free?