Creating a loop as part of a presentation (Preamble)

[Jamtart]

I have to give a presentation in front of a few hundred people in a few weeks and I got this huge ppt presentation that is complete. But I need to create a loop of about 10 slides that will play automatically as the audiance is assemblying. I would like it to be in the same ppt presentation so that I can start the lecture without stopping the loop to go to another file.
I hope this makes sense, and also hope it can be done. I once saw a tutorial about something like this some time ago but I cannot find it now.

UPDATE:
I may have found the tutorial I was looking for:
http://www.pptalchemy.co.uk/PowerPoint_Loop_Intro.html