Concatenate data in a Sub-report then copy in the Main report

Question

Hello,
I'm using Crystal Report XI R2, I succeed to retrieve data as decribe in SAP Note 1212454 - How to Share Subreport Data with the Main Report
But when I hide section A, my values in section B are empty
So my answer is, how to retrieve dataset from the subreport group Footer Group concatenated and show it as a Header group data in the Main Report

Answer 1

I'm currently trying was is explained in:
1218324 - How to suppress a subreport but still evaluate and pass a shared variable
Symptom
In Crystal Reports (CR), subreports are frequently used to calculate and pass data to the main report. In many instances the business requirement is that the subreports not be visible to the end users. However, suppressing the subreport object or suppressing the section of the main report in which the subreport is located causes the shared variables to display incorrect data when passed to the main report.
How can you suppress a subreport but still pass a shared variable with the correct data?
Resolution
In Crystal Reports 9 and later, you can suppress a subreport but still pass a shared variable with the correct data to the main report by following the steps below:
In the Subreport
1. Remove all conditional suppression formatting formulas.
2. Delete all drawing objects such as boxes, lines, etc.
3. Suppress all remaining subreport objects such as database fields, formulas, etc.
4. For all sections that contain no objects, select the 'Suppress' option in the Section Expert.
5. For all sections that contain suppressed objects, select the 'Suppress Blank Section' option in the Section Expert.
In the Main Report
1. Select the 'Suppress Blank Subreport' option in the subreport Format Editor.
2. Remove all borders from the subreport object in the subreport 'Format Editor'.
3. Select the 'Suppress Blank Section' option in the 'Section Expert' for the section containing the subreport.
Background Information
When working with subreports, the 'Suppress Blank Section' option forces CR to evaluate the subreport contained within the section to determine if the final subreport output is blank. The 'Suppress' option allows CR to bypass the subreport completely, because the section is suppressed. By forcing Crystal Reports to evaluate the suppressed shared variable formulas in the subreport, the data can be correctly passed from the subreport to the main report even though the subreport is not visible to the end user.