There is really, no known way that i know of......
Are you by any chance, trying to make a slideshow....of just photos.....
Cause if that is true, you dont have to use powerpoint.
Irfanview has many nice features, including full screen stretching, aspect ration retention, randomization, sorting, saveing of slideshows....make of screensavers....
AND you can import hundreds of images at a time.....and you can save their configurations to a text file....