Using a variable for an instance name?

Ok, I’ve been at this for 2 days now, and really need some assistance. It seems like it should be so simple! Tried some other web resources but so far no luck.

The part that doesn’t work:

 Code:
 on(release){
//None of these work:
critter_pressed_new.gotoAndStop("poof");
_root[critter_pressed_new].gotoAndStop("poof");
[critter_pressed_new]gotoAndStop("poof");
this[critter_pressed_new].gotoAndStop("poof");

}
Where, “critter_pressed_new” is not a specific instance name, but rather a variable name.

Please see the attached file and take a look if you are familiar with variables.

If you want more info, here’s the deal…

I randomly launch some movie clips from the library with attachMovie (they are bedbugs). No problem there.

On launch they get instance names. The first one gets “critter_launched_01”, the second “critter_launched_02”.

There is a button in the root that needs to be able to make the critter go away (by going to a frame label of “poof”, which has a red X on it for now).

I have a little test button that is hard-coded for:
Code:
on(release){
//this is what code needs to do from other button, but using var name:
_level0.critter_launched_01.gotoAndStop(“poof”);
_level0.critter_launched_02.gotoAndStop(“poof”);
}
and it works fine. No problem there.

But, I need to be able to have one button close only the most recent bug. So I created a variable in the root to keep track of the last one out:

 Code:
 var critter_pressed_new = "test"; 

Then within the critter mc I update it using this:
Code:
_root.critter_pressed_new = targetPath(this);
which now makes the variable of “critter_pressed_new” have the instance name of the movie clip in it (which, would be _level0.critter_launched_01 or 02).

Then that button in the root should be able to take the value that is in the variable “critter_pressed_new” and use that as the instance name, to make that particular mc go away.

Please help if you can offer any advice at all!! Thank you!