Summarizing internal tables

I am extracting data into internal table which 6 fields of which 4 are char type and 2 are curr type.

My concern is if all the 4 char type fields match then i want the curr fileds of the all records to summed and displayed as single entry.

eg:    itab-a    itab-b   itab-c    itab-d      itab-e     itab-f
        123        345     ab          cd          2300     3400
        123        345     ab          cd          4000     5000

Now instead of those two entries i want a single entry to be displayed in the report output.

like

       123        345     ab          cd          6300     8400

How can i achieve that...