Maintaining durations in sequence

Hi all,

I hope this makes sense...

Basically, I've gotten a slideshow prepared that goes perfectly with the music - which involves many duration changes that I had to meticulously go through and tweak manually for each photo. Now we want to completely rearrange everything, and I'm trying to avoid having to go through and fix each individual duration to what I want again (mostly because I'm thinking this will be an iterative process and this won't be the last time we rearrange things). Any ideas on how to set up a sequence of durations for photos that is independent of the actual photos themselves?

Example: Photo 1 (3s), Photo 2 (5s), Photo 3 (8s). If I want to rearrange the order to Photo 3, Photo 1, Photo 2...is there a way to set things up beforehand so the durations of 3s, 5s, and 8s stay in the same order regardless of what photo is plugged into that position instead of the photo taking it's duration with it?

Any help you can provide will probably save me a lot of time and will be greatly appreciated.

Thanks!