I think you will find it easier to put your totals on the top row,
above any headings you might have. The formula in column D, for
example, would be:

=SUM(D3:D65522)

This will cover almost the whole column, and will allow you to put
values in any row as the year progresses. By positioning your cursor in
cell A3 and selecting Window | Freeze Panes, you can fix the top two
rows so they will always be visible as you scroll down the sheet.

Hope this helps.

Pete