Sum specific number Non Blank Cells

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

Hi SixthSense

Thanks for the prompt response

I've worked on the a few stuff since yesterday but still stuck with the same problem. I'm trying to figure out the formula for MPP column(E).

MPP = (SUM of last 14 days) - (2 Worst days)

Currently, I'm using

SUM(LARGE(*range*,{1,2,3,4,5,6,7,8,9,10,11,12})) where *range* is something like B2:B21

but I need to manually change *range* on some cells because of blank cells. Sometimes the range includes more than 14 nonblank cells and sometime the range has fewer than 14 nonblank cells.
Is there a way to figure out the exact range that include 14 nonblank cells?

If you have any other questions let me know. Thanks for your help.

Hi. I think I figured it without a helper column.
=SUM(LARGE(OFFSET($E$1,MATCH(LARGE((E2:E500<>"")*(ROW(A2:A500)-1),14),(E2:E500<>"")*(ROW(A2:A500)-1),0),0,MAX((E2:E500<>"")*(ROW(A2:A500)-1))-LARGE((E2:E500<>"")*(ROW(A2:A500)-1),14),1),ROW(1:12)))-SUM(SMALL(OFFSET($E$1,MATCH(LARGE((E2:E500<>"")*(ROW(A2:A500)-1),14),(E2:E500<>"")*(ROW(A2:A500)-1),0),0,MAX((E2:E500<>"")*(ROW(A2:A500)-1))-LARGE((E2:E500<>"")*(ROW(A2:A500)-1),14),1),ROW(1:2)))

After entering extra numbers to your sheet you should enlarge the range in function too.

Hi PhamsO
I forgot to tell what my formula is about. Maybe that is what you dont want. Formula I put posted above takes last 14 nonblank cells and sums largest 12 - sum smallest 2 numbers.
I hope that is what you want. If not please correct me

Hi everyone
Thank you for your help. The solutions from sixthsense and daddylonglegs worked perfectly.
I am still trying to understand how your formulas work. I don't know much about array formulas.

Eisayew. Thanks for you input. I think you misunderstood me. Sorry that I wasn't so clear. I was trying to calculate the formula for MPP (column E) which looks back at the past 14 days (column B) and sums 14 days and minus the 2 worse days. The solution you gave calculated using MPP instead of days. But i think it could of work if the formula was changed to used days.

Thanks again for everyones help. I really appreciate it.

Phams0