Manipulating the structure of a group tree

Hi,

I am using Crystal Reports XI (Release 2) in C#.Net for a Web page, which upon request, gets dynamic data from MSSQL Server 2000, applies the .rpt template and then exports the report to a PDF file.

Let's say that the following is the data i'm using:

Col1    Col2

value1   abc

value1   abc

value1   def

value1   def

value2   abc

value2   abc

value2   def

value2   def

It would be desireable for me to produce the following bookmark tree structure:

value1

 def

value2

 def

So, my goal is to exclude the first node of the sub-group ("abc"). I know that if I group the report by Column1 then Column2, and then use the new "Create Bookmarks From Group Tree" feature, the following bookmark tree structure would be generated:

value1

 abc

 def

value2

 abc

 def

I'm thinking if it is possible to maybe manipulate some "GroupTree" object(does it exist?) during run time or to create a formula in the .rpt template to remove the first sub-group node.

Thanks in advance for your input.