Ok, I think this should help:
Your movie clip name can't start with a number, according the flash syntax it either has to start with an underscore, letter, or dollar sign. <-- I don't know why the hell they made it a dollar sign, but that's how it is.
For holding the name of the clip, you can store it like this using the movieclip._name property
For your instance that we name mc22.
var movieClipName = mc22._name;
the value of var is now movieClipName = "mc22";
Hope this helps!