This may be a trivial problem, but it has me slightly bugged. Is it
possible to count the number of times an Excel cell has been clicked
on?

What I have in mind is, for example, an array of cells from A1 to I10,
and a corresponding array from A11 to I21.

The idea is that if a cell in the upper array is clicked, the
corresponding cell in the lower array is increased by one. Thus if C3
is clicked, C13 would by incremented.

Is such a thing possible and if so, how?