Incrementing one value in an Excel formula

Question

I have a formula in Excel that looks like this:

=VLOOKUP(posts!C12,users!A2:B1800,2)

I would like to duplicate this formula down the whole column, however, I would like C12 to increment (C13, C14, C15 etc), but for the rest of the formula to stay the same.

So far, I have tried duplicating it manually onto the next 4 or 5 cells, then selecting those and double clicking the bottom right hand corner of the selection, however this doesn't work, almost, but not quite.

Answer 1

Add a dollar sign $ before each coordinate that you want to be fixed. I.e., if you want C12 to turn into C13, do $C12 and the C will be fixed but the 12 will increment. IF you want both values to be fixed, use $C$12.