Select a cell with the formula in it, built up in such a way that when it is
extended that it will be like you want it to be, then in the 'Name Box' enter
the range you want to fill with the formula. The 'Name Box' is the place up
at the left side of the formula bar where the address of the cell you have
selected normally appears.
Next use [Edit]-->[Fill] from the menu and choose which direction to fill
based on the first cell you have selected.
Example: you have a formula in B2 something like
=A2 * 3.14159
and you want to fill that down to A550,
choose cell A2, then enter A2:A550 in the Name Box, click [Edit] in the
menu, choose Fill and then choose Down.
