I have a sheet full of daily sales numbers, and I would like to make a
weekly report sheet using the data from it. However, I have not been
able to figure out, or google-out how to do a couple of the things I
need to do:

1) I would like to sum daily sales by =weeknum(), but don't know how.
What I mean is that I would like sheet 2 to be in the format:

Year Week Sales
2001 52 $2338.41
2001 53 $589.88
2002 1 $1769.17

pulled from data like this in sheet 1:

date week sales
12/24/2001 52 $316.97
12/25/2001 52 $345.00
12/26/2001 52 $301.75
12/27/2001 52 $1,006.09
12/28/2001 52 $72.53
12/29/2001 52 $0.00
12/30/2001 52 $296.07
12/31/2001 53 $589.88
01/01/2002 1 $522.91
01/02/2002 1 $465.43
01/03/2002 1 $605.35
01/04/2002 1 $40.68
01/05/2002 1 $134.80

any ideas how to do this?