ERW level break footer on more than one fields

On the ERW in 9.1 I would like to know if I can create level break on 2 fields on a section. For example we have 2 category codes and this is how we want the output:

Main section:

Cat Cde 1     Cat Cde2     Amount

100                    A               1

100                    B               2

100                    C               3

200                    A               4

200                    B               5

300                    A               6

I can create a Level break footer on Cat Cde 1 or Cat Cde 2, however I would like to have a subtotal first by cat cde1 and then cat cde 2 as it appears above.