The difference is to be subtracted from those cells so that it becomes zero. There is nothing to do where there is no Value. vba or formula required.

[KJAYPAL200]

AGEING-MrEXCEL.xlsx
	A																						W	X	Y	Z	AA	AB	AC	AD	AE
1	Sundry Debtors
2	Group Summary - AGEINGWISE
3
4	As on 31 Oct'2023
7	Particulars																						0-90d	91-120d	121-150d	151-180d	181-360d	above 360	TOTAL		DIFF
8																							STILL 0	SUBSTRACT FROM THIS	THEN CHECK IN THIS, NOTHING FILL 0	THEN CHECK IN THIS, NOTHING FILL 0	THEN CHECK IN THIS, NOTHING FILL 0	FIRST CHECK IN THIS, NOTHING FILL 0
9	A A Agro																						-	1,07,602.00	-	-	-	-	1,07,602.00		10,000.00
10
11																							STILL 0	STILL 0	STILL 0	STILL 0	STILL 0	NO DIFF, DO NOTHING
12	AABA																						-	-	-	-	-	65,501.00	65,501.00		-
13
14																							AFTER FILLED 0 IN AB13, NOW DIFF WILL BE 23538.25, SUBSTRACT FROM THIS	STILL 0	STILL 0	STILL 0	STILL 0	FILL 0 IN THIS, THIS 7721.25 LESS THAN DIFF VALUE.
15	Abhinav																						27,000.00	-	-	-	-	7,721.25	34,721.25		31,259.50
16
17																											DO NOTHING, BECOZ NO DIFF	DO NOTHING, BECOZ NO DIFF
18	ABHISAI																						-	-	-	-	19,62,334.00	12,32,666.00	31,95,000.00		-
19
20																											NOW SUBSTRACT 5423481.32 FROM THIS	FILL 0 IN THIS, BECOZ THIS VALUE LESS THAN DIFF VALUE.
21	Ankur																						2,57,396.00	2,05,498.00	-	5,25,000.00	65,53,004.00	3,26,706.32	78,67,604.32		57,50,187.64
SD AGEING (BANK) (New) (2)

Cell Formulas
Range	Formula
W9,W21,W18,W15,W12	W9	=C9
X9,X21,X18,X15,X12	X9	=G9
Y9,Y21,Y18,Y12	Y9	=K9
Z9,Z21,Z18,Z15,Z12	Z9	=O9
AA9,AA21,AA18,AA12	AA9	=S9
AB9,AB21,AB18,AB12	AB9	=MAX(0, IF(S9=T9, R9, IF(S9-T9<0, U9, R9)))
AC9,AC21,AC18,AC15,AC12	AC9	=+SUM(W9:AB9)
AE9,AE21,AE18,AE15,AE12	AE9	=+AC9-E9