Return Column where number drops Below zero

[BellaxPalus]

I have been trying to figure out how to get the excel to return the column that causes the value of a cell to drop below 0. Ie A1=3 B1=5 C1=5 so A1-B1-C1=-7 but Column B is where the 0 value is passed. Must not have VBA for the environment that I work in. The Total TDY of 65 is listed in B2 and I use

=$B$2-SUMIF($C3:$AA3,"<>",$C$2:$AA$2)

to calculate the numbers of days remaining in the travel year for each individual. The number of days that are subtracted for each trip are listed in Row 2. I need to be able to list which trip causes each person to go beyond their maximum in another cell on the page. Below is a sanitized excerpt of my sheet. Thank you for your assistance.

Names

Total TDY

Trip

Trip 2

Trip 3

Trip 4

Trip 5

Trip 6

Trip 7

Trip 8

Trip 9

Trip 10

Trip 11Trip

12

Trip 13

65

15

16

13

20

12

20

19

12

20

20

13

17

19

Person 1

-13

x

Person 2

-29

x

x

x

Person 3

-21

x

x

Person 4

-30

x

x

x

Person 5

-24

x

x

x

Person 6

-32

x

x

Person 7

-3

x

x

Person 8

30

x

x

Person 9

7

x

Person 10

21

x

x

Person 11

45

Person 12

65

Person 13

65

<tbody>
</tbody>

	Over TDY Use during:
Person 1
Person 2
Person 3
Person 4
Person 5
Person 6
Person 7
Person 8
Person 9
Person 10
Person 11
Person 12
Person 13

<tbody>
</tbody>