Pivot table, cannot determine a simple function based on years dimension

[#1]

Hello all!

I need your help urgently, so every small information will be usefull for me.

I have 2 tables that I am loading.

tab1:

ID	event_year
1	2011
1	2010
2	2011
2	2009
3	2011
3	2010
3	2009

tab2:

ID	pay_year	ACC
1	2011	100
1	2010	110
1	2010	120
1	2009	200
2	2010	210
2	2009	130
3	2011	150
3	2011	180
3	2010	170
3	2009	500

with the information from these 2 tables, I would like to make a pivot table that should look something like this:

event_year	0	1	2
2009	sum(ACC) for event_year & pay_year+0	sum(ACC) for event_year & pay_year+1	sum(ACC) for event_year & pay_year+2
2010	sum(ACC) for event_year & pay_year+0	sum(ACC) for event_year & pay_year+1	-
2011	sum(ACC) for event_year & pay_year+0	-	-

*the 0,1,2 values that are added to year3, belong from the table header.

I don't know how to make an expression for this...I searched all over the community, but no result.

To make a better idea of what I am searching for, maybe this table will explain:

event_year	axa_y	0	1	2
2009		sum(ACC) refering to 2009-as pay year	sum(ACC) refering to 2010-as pay year	sum(ACC) refering to 2011-as pay year
2010		sum(ACC) refering to 2010-as pay year	sum(ACC) refering to 2011-as pay year	-
2011		sum(ACC) refering to 2011-as pay year	-	-

So:-the first collumn (0) must show all the ACC that are done and paid in the same year

     -the second collumn(1) must show all the ACC that are done in event_year and paid in the next year

     -the third collumn(2) must show all the ACC that are done in event_year and paid 2 years further.

What I have tried so far, but garbadge result:

I have created an internal table somehow to add the 'axa_y' to the year field....I don't know if this can be a solution...

axa_y:

LOAD * INLINE [

axa_y

0

1

2

];

after that I have created a pivot table with the dimensions 'event_year' and 'axa_y' and at the expression I have the following:

'=if(pay_year=event_year+axa_y , sum( ACC))'

but still no result...

Please help me because it's urgent, and sorry my english in this post.

Thank you very much,

Silv.

[#2]

A small completation for a better understanding

the calculation fields must show something like this (but I don't know how to put this in the expression):

sum(ACC for 'event_year', 'event_year' + 'axa_y')

where 'event_year' + 'axa_y' is refering to 'pay_year'