Export Settings for Transparent Background Video that PowerPoint Accepts?

Hello Community! I have a video clip featuring a transparent background that I'd like to insert into PowerPoint. I've tried exporting it as both a .MOV and a .AVI. The audio comes through perfectly; the video does not. Depending on what I've tried, PowerPoint either accepts the video, but the background is black (which I've confirmed is not the case within Premiere Pro), or PowerPoint throws an error message regarding the codec and 64-bit. Any guidance would be greatly appreciated!