route all uri to one special uri except some cases

I want all uri of my site route to one controller. Except The uri starting with home, admin, login or sigun_up will not route to that one controller. How would you do that?

I'm thinking some kind of reg ex, something like this

$route["all link route to this bosss controller, except uri starting with admin, login, home and sign_up"] = 'boss controller';