Experts Help!!

[knip]

Hi All,
        I Have a report where i have product group,products and categories

Let say Health Drink is my Product Group which has Products Horlicks,Complan,Boost etc, now thier can be other product group say Foods
Now each product has four categories A,B,C,D which gives different characteristics of product
Health Drink
Horlicks
A
B
C
D
Boost
A
B
C
D
Complan
A
B
C
D
Grand Total Health Drinks  A  (Sum of all A's)
                                           B (Sum of All B's)
                                            C (Sum of All C's)
                                            D (Sum of All D's Above)

Foods
Similarly will have for different product groups

Please let me know how to achieve this?

Note:  All values are data items, no hard coded values