Wondering if someone can help me with a formula. I would like to calculate
the subtotal for a given month, where the month is in 8/12/2008 format.

After calculating the subtotal, would like the total to be placed into a
specific column that I specify. Also would like the totals to be updated if
new info is inputed.

Can someone help me out where to start and what I need to do?

Thanks.