Another Obscure Excel Question

Deaths/incident by weapon type.  I have a column with all the weapon types: A.  I have a column where I total the incidents by weapon type: =COUNTIF(massmurder!AD3:AD297,A2)
I want to sum the total dead in massmurder!AD3:AD297 by weapon type, but excluding cells which are =SUM formulae, because some rows are sums of dead per decade or century.  I would think that there is a way to say sum all numbers in a particular column if the cell in that row matches some other cell.  And then excluding rows that have a SUM function in that column or the word "total" in a cell in that row or some other cell that is distinctive (the subtotal rows have a sum of incidents where individual rows are blank in that column).

This may be easier to do by exporting the spreadshheet as a CSV file, then using grep and awk to produce a CSV file containing the data that I want.