I think you might be referring to Edit | Fill. Type your first entry
(1) in the first cell of a blank column. Highlight that cell down to
5000. Select Edit | Fill | Series, and you will need Linear with a Step
Value of 1. Click OK and your rows will be numbered.

You could also use the formula =ROW() and copy down, then fix the
values with <copy Edit | Paste Special | Values | OK then <esc or
<enter.

Hope this helps

Pete