Targeting A dynamic Textfield

Ive been talking about this in another thread, but I guess its a better idea to start a new thread to ask this question: How can I target a named instance of a dynamic text field that is inside a button, which is inside a movie clip, which is on the root timeline, from a frame in the root timeline?

I tried _root.movieclipname.buttonname.txtfieldname but that doesnt work…and to make issues a little more complicated, its not a static movie clip, but a duplicate that needs to be targeted every iteration of a ‘for’ loop.

I thought it would be something like -

_root.movieclipname*.buttonname.txtfieldname

But thats not working…How can I target that textfield?