ok, I don't remember the EXACT code to do, but in director you will need a handler for external events
on evalscript vExternalRequest
....place logic code here
end
then in your flash you need to pass out a command, I think its via the FSCommand but I could be wrong (I'm not much of a flash user), could be via a getURL but try FSCommand first.
Now the way I do this is my evalscript code is this (code may not be 100% correct)
on evalscript vExternalRequest
do vExternalResuest
end
then the FSCommand from flash may be something like
go to frame 10
sprite(20).visible = false
or any other single line of code. I also use calls to other handlers for example
MoveToFrame("framename"

and have a handler called MoveToFrame.
hope this all helps a bit.