Hello
im using SunOS and its great , I know I can setenv global environment variable per user
but my question is can I setenv global environment variable in more higher level ( maybe some kind of root user or something) so that every users will
see the same value of this global env

Environments are local, per user, not global.

You should be able to set global env vars in /etc/profile if logging
in under the ksh shell or /etc/.login under the csh shell.

These files are used at login prior to executing the users local
environment.

And setting those variables readonly makes them changeproof by the user.