Customer portal users and data visibility on reports

Customer portal users and data visibility on reports

Hi,

Suppose I have two companies Rocket Science (RS) and Quantum Politics (QP) as my customers. Both companies access the application through the customer portal. When a customer portal user RS A fills data in a form, the user RS  A can view the data in the corresponding report. The same is true for a customer portal user RS B. The user RS A can't see RS B's data and the user RS B can't see user RS A's data on the report. If permission set is configured to "View all", then all the users will see all the data on the report. And there is the issue, because then the users of the both companies RS and QP are able to see each other's data, which is no good.

I tried to solve the issue through permissions and the filter, but it doesn't work, because the filter on the report only accepts static strings or values - not variables.

Has anyone found a solution or workaround on this? Or is the only workaround to set-up a HTML page and control contents through Deluge? 

I found some questions and discussions around similar topic, but not really answer.

br,
-rj