Use values from populated matrix for calculation

Hi I am new to reporting services and plodding along slowly. I will try and explain the best i can.
I have a matrix table which groups columns by year then has 3 row groups :-

08/09 09/10
column 1 2 3 column 1 2 3
Row1
Row2
Row3


How do I use the data from column 1 row 1 from each year i.e .compare column 1 row1 08/09 against 09/10 and see if the value for 09/10 is higher. I don't know how to reference the specific cell for each year, there can be multiple years in the matrix depending on the selected parameter, but I want to compare the last/latest year selected with the previous.

Is this possible!!!!

Thanks in anticipation