Hi Guys
I have a little project that I have been working on and I can't figure out how to sum the 12 largest of last 14 non blank cells
My excel is set up as follows.

A B C
1 9/1/2012
2 9/2/2012
3 9/3/2012
4 9/4/2012 720.79
5 9/5/2012
6 9/6/2012 1080.88
7 9/7/2012 1560.56
8 9/8/2012
9 9/9/2012
10 9/10/2012 -440.67
11 9/11/2012 870.11
12 9/12/2012 1240.05
13 9/13/2012 2200.3
14 9/14/2012 300.75
15 9/15/2012
16 9/16/2012
17 9/17/2012 -1150.37
18 9/18/2012 830.87
19 9/19/2012 1790.84
20 9/20/2012 4900.82
21 9/21/2012 2200.43
22 9/22/2012
23 9/23/2012
24 9/24/2012 560.26
25 9/25/2012 3830.08
26 9/26/2012 1520.28
27 9/27/2012 -4650.37
28 9/28/2012 8310.93
29 9/29/2012
30 9/30/2012

The part that has me stumped is that the ranges sometime change because of blank cells.
For example
C27 will use range B10:B27 (18rows because 4 blanks)
C26 will use range B7:B26 (20rows because 6 blanks)
C24 will use range B4:B24 (21 rows because 7 blanks)

I would deeply appreciate any help.

Thanks,
tom