Target a textfield inside a symbol?

I have a symbol called Rectangle and a text field called Counter on the stage. Inside the symbol I have another textfield called Counter2. For the .click event of the symbol I have:

sym.setVariable("checker", "1");

sym.$("Counter").html(sym.getVariable("checker"));

sym.setVariable("checker", "0");

sym.$("Counter2").html(sym.getVariable("checker")); //error here?

But I noticed that only Counter is being changed and that Counter2 was not targeted. How do I target Counter2 without having to move it to the main timeline?