Hi terrifromreno,
Thanks for visiting Apple Support Communities.
If you want to export a PowerPoint presentation to a playable DVD (that can be played in a standalone DVD player), you'll have to go through a few steps.
The first step is exporting the slideshow as you've tried. Be sure to export the .mov file using the steps outlined in this Office Support document:
Save a presentation as a movie file - PowerPoint for Mac
It looks like you'll have a choice of "size and quality" when exporting the movie. For a DVD, you'd choose a size of 720x480 (or equivalent option) in the settings.
Next, you'll need to burn the DVD. If you don't already have a DVD burning application, you can find several in the Mac App Store. Generally, the option to loop the video is set in the application that you use to burn the DVD. The DVD player itself may also have this option.
Be sure to test the finished DVD prior to the event itself.
Additionally, please let us know what version of Mac OS X you're using if you need more help.
Cheers!