A family of Microsoft presentation graphics products that offer tools for creating presentations and adding graphic effects like multimedia objects and special effects with text.
The trick John wrote up will work in all PowerPoint versions from 2007 onward and doesn't require an add-in.
It does, however, require you to save the presentation containing the code as a PPTM rather than a PPTX. Depending on the end user's security settings, it may not work.