I have a spreadsheet that I need to reformat each month in order for it to be
imported into another application. The spreadsheet varies in length each
month, from say 100 lines one month to 600 lines the following month.

I have recorded a macro that deletes columns, creates formulae etc.
I wish to 'auto fill' the formulae I create down the entire length of a
column. However, the fact that the spreadsheet has a different number of
lines each month means that performing the autofill via a simple macro does
not work.

I know there is a bit of code that will allow me to find the last line in
the spreadsheet and autofill down to that line but I can't remember how to do
it. Any suggestions?

Thanks in advance