CVSROOT redirection

[Dusan Juhas]

Hi folks,
is it possible to override CVSROOT in commitlog?
I have 2 repositories. Let's call them _local_ and _remote_.
_local_ is a read-only mirror of _remote_.
I'd like to run all read-only cvs commands on _local_ (esp. co).
The rest of commands should be used with _remote_.
I'd like to check in _remote_ without changing administrative
files in the sand box (even without changing CVSROOT).
Is it possible to arrange an commitlog action which
skips checkin in _local_ and redirects all actions to _remote_?
-- 
Best regards,
Dusan Juhas