Goal Seek
Hi Claudio
Goal Seek is a What-If Analysis tool in Excel.
With Goal Seek you can set a formula to a new value (Goal) and then specify which one of the cells that the formula referenced as the cell to be adjusted.
If the selected cell is formatted as a percentage them you can enter the new Goal in the Set Value box as a percentage. The computer will take it into account in the calculation.
Hope this helps
Carlos