Unsetting ForceCommand in openssh

[Lars Nooden]

I'm looking at the configuration for OpenSSH_5.3 and wish to force
commands and chroot all users, except one group.  What is a way to unset
the 'ForceCommand' configuration directive?

Here's the way that doesn't work, but shows the approximate goal:

        ...
        ChrootDirectory /var/www
        ForceCommand internal-sftp

        Match Group wheel
           ChrootDirectory none
           ForceCommand none

'none' seems to work for ChrootDirectory but not for ForceCommand.

Regards
/Lars