layers (and scenes) don't exist as such in your published
swf. they are strictly an authoring environment feature: your
objects in different layers are assigned depths upon publication
and that info is used by the flash player to render your swf. and
your scenes are laid end-to-end in the published swf and rendered
as one timeline.
so, layer names (and scene names) are irrelevent.
to access a variable it need only exist and you need only
specify the correct path/name.