I wish to create a macro that will perform functions upon multiple rows of
data. The number of rows of data will change every time.

Problem : I create a macro by recording. I select rows of data using
CTRL/down arrow on the last column and then selecting back to the first
column of the first data row. This appears to 'hard code' the number of rows
of data to be the number of rows that exists at the time of macro creation.

When I run the macro another time it then selects the same number of rows as
when the macro was created, which will then not match the new current data.
i.e. some rows are left unselected.