Using variable value to refer to a movieclip on stage

Basically I have a variable in which I store various numbers depending on other aspects of the flash movie and I have a bunch of movieclips that are on the stage all named by number.
I want to use the variable value to access and run methods etc of these movieclips.

e.g.

var myVar = “10”;

myVar.myFunction();

where the item on stage called ‘10’ will react. I realise this is a confusion between a string and an object/movieclip reference but i’m almost certain ive done this before and ive got a feeling it had something to do with [ ] brackets on the end of something…

sooo frustrating when you can’t remember stuff