New Post: Inserting formula problem

I am trying to insert, using a loop, a formula that references another worksheet. Something like this:

" =$'ESPECIFICO - SIMULAÇÃO'.AG14/AD8 "

The problem is that, after saving and opening the my workbook, the formula does not work. And I found that if I just enter on the cell's formula, copy and past it again, without changing anything, then the formula will work.