Caluculate Values based on text in cell - in the next coloumn

[ramana1983]

Hi Friends

i have text in coloumn 1 and values in coloumn 2

i need calculate difference of values and percentage between the occurances based on text in column 1

please help

Coloumn A	Coloumn B	Coloumn C	Coloumn D
Enter	AE		(AE-AK)/AK
Hold	AF
Hold	AG
Exit	AH
Exit	AI
Exit	AJ
Exit	AK	(AK-AQ)/AQ
Hold	AL
Hold	AM
Hold	AN
Hold	AO
Hold	AP
Enter	AQ		(AQ-AS)/AS
Hold	AR
Exit	AS	(AS-BF)/BF
Hold	AT
Hold	AU
Hold	AW
Enter	AX
Hold	AY
Hold	AZ
Hold	BA
Enter	BB
Enter	BC
Enter	BD
Enter	BE
Enter	BF