As I might have told you then, if you use the combobox from the toolbox it is not directly accessible. First the combobox needs to be bound to a cell and then you use that cell to do what needs to be done.
If you want to use it on userform then you have to make use of rountine
Private Sub ComboBox1_Change()
Note:ComboBox1 would be the name of the dropdown on the form
and instead of "cells(1, "A") " as in the code you would be using