Is there a way to count to the end of a column when you are not sure how long
the range is? I have functions that use the SUMPRODUCT to count various
series of data in other worksheets, but each month new data is added to those
worksheets and I have to keep editing the functions. Otherwise I have to use
set the functions to count out well beyond the data which is slowing down
Excel.

Any help would be apprechiated.

Using Excel 2003.