Hi Pavel,
OpenDocument is the best available option to view documents dynamically in a BI 4.0 system.
OpenDocument is a web application deployed within a BI platform installation. It processes incoming URL requests for documents in business objects enterprise, and delivers the document to the end user in the appropriate viewer.
It allows you to send users direct links to a document and avoid having them navigate through a folder hierarchy, such as in BI launch pad.
To authenticate the users without prompted for credentials, you can develop a jsp code to create a valid session object against CMS (Central management Server) and redirect the users to the opendoc url.
In order to make this operation dynamic, you can pass report identifier (SI_ID/SI_NAME/CUID) in the url to call your jsp page.
Retrieve this parameter in the jsp code and pass it to the opendoc url to redirect the user to the requested report.
For detailed information on how to implement this scenario, refer to the document available here.
Hope it helps.
Regards,
Anchal