Using variables as movieclips

Whats up everyone,

I need to know how I would use a variable as a movieclip, like me expain with an example:

currentMovie = “MovieClipName”;

_root.currentMovie.gotoAndPlay(2);

I want to have ‘MovieClipName’ to be the movieclip that plays.
But obviously AS 2 things I’m asking for ‘currentMovie’ to play but its just a variable.

How can I implement this? Help Please?

Thanks.
Noir