How to grant authorizations at report's parameters level

Dear Guru,

I would like to understand if it is possible to give the authorizations to execute a report but only with the possibility to input/change some parameters.

Example: a report can be executed in test mode and normal mode, activating a flag in the selection-screen.

The need is some users can execute the report only with test flag activated, without the possibility to change it.

Is there any authorizations object I cna use for this? Do you have any suggestions to manage the case?

The report is standard and SAP does not provide a "test" transaction (like PC00_M**_CALC_SIMU).

We do not want to create a copy of the report and modify it.

Thanks a lot for your help and Best Regards,

Gaetano