An example of what Im trying to do:

Four cells in the same column A1:A4 with values 1,2,3,4 respectively.

Assuming that the value of A4 factorial, so A4!, would be A4*A3*A2*A1, then
the function I am trying to insert would be A4!*A3!*A2!*A1!.

I want it to be, however, so there is an input cell where I can insert the
number of cell's I want included, which in this case was 4.

While this is relatively simple if there are just 4 cells involved,
ultimately I will be using up to 100 cells. As yet I have not been able to
produce an appropriate function to do this, and am not even sure if Excel is
able to do this. Any help is appreciated.