Targeting Paths in external SWF

I need Help and his for targeting objects

This is a tree to the button in the SWF i want to control

MAIN v
Navigation v
Container v
Content v
Button

Navigation is loaded into level 10
click on a link and load an SWF into container MC
click a sub link and load another SWF into content MC
Additional buttons and content is in the SWF loaded into the content MC

How do you navigate through each SWF EXAMPLE - from the SWF loaded into containerMC i want to play a MC loaded in the content MC. (would i use _root.container.content.InstanceName.play()???)

Please a tutorial, a book, a hint, anything you have to offer is greatly appreciated.