How to hide some variables on variables screen in web report (in WAD)

I need to hide some optional variables (not all of them) on variables screen in web template.

Hiding the whole selection screen is not an option, since users have to populate other variables and some variables are mandatory.

Web template is based on a query that can be run in BEx Analyzer by superusers - and there they need all variables. I want to use the same query both in BEx Analyzer for superusers and on the Portal for regular users. For portal version though I need to hide some of the variables on the selection screen. Is it possible at all?

I would like to avoid creating two separate queries - one for Analyzer and one for Portal.