Grouped Records

Does anyone know of a good method to create a combined record based on grouped columns?

For instance, records (rows) are grouped on column 1 and 2:

Col 1
______
         | Col 2
         |______


         Col 1 | Col 2 | Col 3 | Col 4
         -------------------------------
Row 1|   A    |   B    |    C   |   D
--------------------------------------
Row 2|   A    |   B    |    E    |   F


a) I want to create a new record when any Rows are grouped.
Example when: (Row 1, Col 1) == (Row 2, Col 1) && (Row 1, Col 2) == (Row 2, Col 2).
My method of finding the first grouped row is pretty convoluted where I have to test all the columns against the ordered column list and so on. Making a new record based on the found row is a simple process of copying the found row record to a new record.

The result should be: New Record (A, B, C, D)

b) Now I want to append whatever doesn't match from Record 2 to this new record!

The result should be New Record (A, B, C, D, E, F)

It seems like it should be simple, but I've really ended up with quite a mess trying to get the collection of rows under the same "grouped by" column(s). Is there an easy method to grab all the rows under a Grouping? Digging through the code I've found the CXTPReportColumnOrder which gives me the ordered column list, but nothing to indicate which rows or records are indeed Grouped.

Thanks in advance for any tips on how to accomplish this.