Moving in to one MC?

Assume the main time line is A.
On A I’ve got movie clip Z
On **A **I’ve got movie clip **B **and inside B I’ve got a movie clip C (I need it to be this way because it soft of a TAB meanu).

My problem is the actionscript written in C makes few objects called **planet 1, planet 2, planet 3 **on A function well. But when I move planet 1, planet 2, planet 3 to a movie clip (planets_mc) it wont function!

How can I put planet 1,2 and 3 in to one mc and still make the actionscript in C work?

I’ve used the _root. command in the script C. Hope my question is clear enough!