Targeting variable mc's

I’ve tried everything. Help would be greatly appreciated!!
Question: How do you target a movieclip instance that was named with a variable? eg…

whichPic=1;
Pictures=10;

–frame2
onEnterFrame = function()
{if(_root.whichPic<_root.Pictures)
{attachMovie(“Picholder”, “Picholder”+_root.whichPic, _root.Depther);
gotoAndPlay(3);}else{stop();}

–frame3
???“Picholder”+_root.whichPic._set_some_type_of_property???
_root.whichPic++;
_root.Depther++;
gotoAndPlay(2);

try [“Picholder”+whichPic]._width = 100;

if that doesnt work (but i belive it should), then try

_root[“Picholder”+whichPic]._width = 100;

I gave that a shot. No go… These actions are in a mc on the stage. the variable “whichPic” is held in _root. I’ve tried:
[“Picholder”+_root.whichPic]._width = 100; and combinations of the like, but they didn’t work either. I’ll keep on playing…
Thanks for the help!!

if you send me your FLA i could take a look at it.

thanks, I figured it out. At least worked around it if nothing else… I put the value for the property I wanted to set in the mc in the library, so when each one was attached, it loaded with that value.
Thanks for the help!