As3 preload swf, play MCs at set percentages

Hello I’m a fan of AS3 not a geinus and this ones given me a brain explosion…

I want to preload a swf and insted of a bar I would like to play 5 mc at intervals trigered by the persentage of the total loaded

I want to set a new loader event of a URL = my_movie.swf
and a progress.complete event

var percent of total loaded
Then - if (percent==20%);{gotoAndPlay (20%movie clip)
then -if (percent==80%);{gotoAndPlay (60%movie clip)

etc. etc. etc.

I’m unsure how to lay out the mc and where to set up the functions in the time line to make them work…as I said my head can’t get around the achitecture and any hints would be awsome.