Unless I'm mistaken, there is a "save as html" option. Microsoft products often have that. However, it creates a monstrosity. Microsoft products mostly do. What I've tried with some success is this:

Open the PowerPoint presentatation in Open office. Then save as html. The resulting code can be fairly decent.

Since my memory isn't what it used to be, I just tested this on a randomly downloaded pps file to see if it actually works, or if I was thinking of two other programs.

It worked. One interesting thing: The original 3.2 megabyte pps turned into a 1.3 megabyte folder (50 something slides).