I have a field contains this value :

ALL, A-1, A-2, B-1, B-3

and the meaning of the value is :
ALL = All classes
x-y = x : class, y = number, so A-1 means class A number 1

I can change the output in form like this :
(if the value in field is ALL, A-1, A-2, B-1, B-3)

All classes
Class A : 1, 2
Class B : 1, 3

And my problem is, i dont know how to change the output like that in report..

plz help me.. thx..