urgent problem: grouping by fields of internal table

Hi friend,

i have a urgent problem and i hope that you can help me out:

i have an internal table containing data, and i sorted it by 3 fields.

now what i want to do is kind of grouping that means that all the lines that are the same should be written into another internal table like this:

A

A

B

B

B

C

D

would give me:

A 1

A 1

B 2

B 2

B 2

C 3

D 4

How could i do this ( especially avoiding nested loops ? ) Is there a handy trick to do this efficiently ?

thank you, i will give points immediately,

Clemens