faking a long transition between stills - iMovie 09

[uncleMonty]

Making a slideshow - I understand you can't have a transition longer than the still photos on either side of it. Is there a way to obtain a long fade-in (say 10 seconds) from white at the beginning of the slideshow, where the first photo starts appearing immediately?

I can have this:
blank white screen (5 secs) --> cross-fade transition (4 secs) --> first real picture (5 seconds),

but this results in 5 seconds where nothing happens, a 4-second fade-in to the first image, then that first image remains on-screen for 5 more seconds.

What I would like is something like this:
blank white screen (0.5 sec) --> long cross-fade (takes 10 seconds for image to appear at full darkness) --> first real picture (stays for 1 second longer, after the cross-fade is completed).

I know iMovie won't let me do it that way if I try to proceed normally. But does anyone know of a way to "fake" this sequence of events? It doesn't sound complicated enough to be impossible...