This is how I would do it:
1. Open the presentation with the unique slide design.
2. Save it to a new name. This is just to protect you from yourself and
prevent an accidental save that would wipe out the original.
3. Delete all of the slides.
4. Go to File > Save as > Design Template (*.POT) and give it a name that you
will remember.
Once you specify the file type as Design Template, PowerPoint will shift and
point to the folder where it expects templates to be stored. Don't override the
location. PowerPoint knows best. <G>
The above method gives you a permanent copy of the template for repeated use in
the future.
If you only want to use it once, just do Steps 1-3 and then start creating your
new slides.
--
Sonia Coleman
Microsoft PowerPoint MVP Team
Autorun Software, Templates and Tutorials
http://www.soniacoleman.com