You can use $ signs to "fix" a range, e.g. if you use this formula in D2 copied down
=COUNTIF(A$1:A$1000,C2)
then when you copy to D3 the criteria will change to C3 but the range will remain A$1:A$1000.
If you want to copy the formula across then use $ in front of the column letter instead.....
regards, barry