I am creating a presentation and was wondering if this was possible in PowerPoint 2007?

I have 2 separate PowerPoint presentations. The first has 50 photos that just fade between each other with audio in the background. I need this to run on a seamless loop before the actually presentation starts (Ex. 20 minutes prior to meeting).
I also have a similar presentation that I want to run later in the meeting. So - 2 separate presentations running independently in one.

Between these I need to display several videos and graphics and have them all seamlessly switch between each other.
Can this be done?

EX.
POWERPOINT INTRO LOOP WITH AUDIO
FADE TO
LOGO
FADE TO
VIDEO 1
FADE 2
LOGO
FADE TO
VIDEO 2
FADE TO
LOGO
FADE TO
POWERPOINT LOOP WITH AUDIO
FADE TO
LOGO