Problem with Group Band

(sorry for my english)

I want to create a particular GroupBand, that's the information:

We have a detail table like this
- IdDetail
- IdMaster
- OrderNumber
- IdGroup
- IdArticle

The order that I need to report it???s:
IdMaster + OrderNumber

The problem it???s that exists records with IdGroup with value 0, that mean: with 0 group, I???dont want to see in the report a blank GroupHeader.

Example of data order by IdMaster + OrderNumber

IdDetail, IdMaster, OrderNumber, IdGroup, IdArticle

1 1 7 0 ART2
2 1 11 3 ART6
3 1 12 3 ART9
4 1 15 0 ART3
5 1 16 0 ART5
6 1 18 0 ART10
7 1 19 1 ART15
8 1 30 1 ART3

I need a detail report like this :

ARTICLE ART2

GROUP 3
ARTICLE ART6
ARTICLE ART9

ARTICLE ART3

ARTICLE ART5

ARTICLE ART10

GROUP 1
ARTICLE ART15
ARTICLE ART3



HOW CAN I DO IT?

Thanks
S.Barco