Iteration in a crosstable column-group

[jbo_master]

Hi,

I have the following crosstable, which contains Products and differnet Seasons. Each product can have 3 Subtypes.
Each Season can have differnet Dateranges.

I defined a row-group that contains the product and another one for the corresponding Subtypes:
I defined a column group for the Season.

Now my problem is: How can I iterate through a list of dateranges that correspond to a specific season as it is shown in the below table??
I thought of placing a List-Component in another Column-group, passing it the parameter that contains the specific season and then it should iterate through the list and show all datenragens in a column.
But it doesn't work.

Any suggestions ??
 

 

		Season A	Season B
		01.01.2009 to 31.01.2009 01.02.2009 to 28.02.2009 14.05.2009 to 16.05.2009	01.03.2009 to 30.03.2009 01.04.2009 to 31.04.2009
Product 1	Subtype A	23.99$	21.87$
	Subtype B	47.77$	95.37$
	Subtype C	28.39$	75.39$
Product 2	Subtype A	2.55$	12.23$
	Subtype B	8.77$	123.23$
	Subtype C	4.29$	1$