Loop search, and calculate with multiple conditions

[christchaaya]

Hello everyone. I'm pretty new to VBA even if I already know how to do basic codes. In this case I have the idea but i don't know how to write it down. I'm working on a worksheet with 12k rows actives, and it's all structured as the table i posted below. What i have to do is substract the initial value (green one) to the final value (red one) and divide it to 1.18 ( if column a is 2012 and the value in b is <= 9) or 1.21 ( if column a is 2013 or it's 2012 and the value in b is >9). Then i have to substract to the result the values in column d that have in column c "aa".

The positive thing is that the dividing line is always 2 rows above the initial value and 1 row below the final value so i thought i can make a loop that search in column a for the value "*******" and then with offset make x= initial value , y = final value and make the operations i told before. ANY IDEA OF HOW I COULD WRITE THIS OR ALSO ALTERNATIVES WAY TO GET THE SAME RESULT ??? HELP IN ADVANCE

	A	B	C	D	E
1	*******	===	===	===	===
2
3		0005PR		100	200
4	2012	02	bb	10	10
5	2012	04	bb	20	30
6	2012	10	aa	20	20
7	2012	11	bb	15	50
8	2012	11	aa	25	40
9
10				190	350
11	*******	===	===	===	===
12
13		0009PR		150	320
14	2012	02	bb	25	35
15	2012	05	bb	10	20
16	2012	05	bb	10	10
17	2012	10	bb	15	30
18	2013	01	aa	30	10
19
20				240	425
21	*******	===	===	===	===

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