Would like a macro to copy a cell down a variable number of rows

[Rod_Bowyer]

I am downloading data from the internet into an Excel spreadsheet. The data varies each time in terms of the number of rows.

I download the data into Column B (there are a number of other columns but I don't think that they matter cuz they are all have the same number of rows - which changes each time I do another download).

I download the name field into Cell A1 and then manually copy it down to each row which contains data about that customer.

When I recorded a macro to copy and paste this customer name into Column A it copies the cell (A1) and then goes to column B - end down to go to the bottom of the data then into column A and shift up arrow to take it to the entire range that I want to copy the name into and then down one. The trouble is that the Macro "anchors" itself at the bottom cell so that each time I run the macro it inserts the customer name the same number of times despite the fact that the number of rows varies each time.

Is it possible to have a macro which will copy the customer name down each time according to how many rows of data the customer has (in Column B)?

Many thanks - Rod Bowyer