Variable of nested MovieClips global coordinates

I have a MovieClip (“mc3” that moves dynamically) inside of a MovieClip (“mc2” that moves dynamically) that is on the stage (“stage” that is static). I need to find the value of mc3’s x in relation to the stage? I need to make it into a variable. I am trying to do the math, can’t figure it out. Also tried localToGlobal and failed. Any ideas?

Bob