OK I think of myself as an experienced excel user but
cant figure something out which should be very basic.

Say I have a formula where the input is cell A6, the
formula in cell A1 is A6*2 and the output is written in
A8.

I now want to compare the answers as if A6=1 through to
A6=100. So I write out 1 through 100 in cells C1 down to
c100. Then in the corresponding cell next to each number
(D1-D100) I want to know the answer of that number
inserted into the function A6*2, without repeating the
function in every single D cell. (In reality the function
in question is actually a very complicated one that I
cant express in one cell, and need to go through the
complicated function everytime).

Therefore what I am trying to do is write something like,
=set(A6=C1,A8) in the cell d2, and have an answer 2. then
in d3 have an answer of 4 and so on......

to translate =set(a6=c1,a8) set a6 to equal c1, so the
input a6 would be 1 in this case, the output should be
the answer in cell a8. In this case 2.

Thanks for help, and my apologies for the long winded
question.
..