Until now, I have copied a formula to all the relevant cells in a column by
clicking on the bottom right corner and dragging down through the rows.

What I need now is to apply the formula to ALL cells in a column. I don't
want to have to hold and drag down through 65000 rows.

Is there any menu option I can use to write the formula I need in cell A1,
then have it automatically apply to cells A2 through A65000 (or whatever the
end row value is).

Thanks for any help.

Gillian