Targeting Mc-s on timeline from inside a second mc

Hi

I have a problem targeting a mc that is on main timeline with button that lies inside a mc that is on main time line. What should code look like to target something that lies on main timeline from some where else.

it is like that:

timeline

  • movie clip that needs to be targeted, another movie clip containing button that needs to target first mc

I am using action script 3. Pls help me as i am still a beginner and i am stuck with this problem for two days in a row now.