Using mc vars in function?

ok, first of all, im not totally sure how to describe my problem so im going to recreate a simple example of what im trying to do…

my problem is that im not sure how to refer to a dynamic mc in a function…i know that sounds confusing but maybe this will help…

lets say i have a function like:

fakeFunction = function (mcName){
// refer to the dynamically targeted mc
_root.mcName._x = 123;
}

the problem with this is that the function looks for an mc titled “mcName”…and the function is hard coded…what i want to do…is to reuse this function with any movieClip on the timeline i want…so how do i refer to the mc in the function dynamically? i hope this makes sense?

ive also tried something like this

_root[mcName]_x = 123;

but this doesnt work either…ive seen something like this done before…using brackets to target an mc with a var…

any help would be much appreciated…

blessings.

take a look at this
http://www.kirupaforum.com/forums/showthread.php?s=&threadid=12082
it should help