symfony patten regex trick

I have my firewall on symfony, and I want it to work on all the site except a specific folder.

something like this:

  members_secured_area:
                pattern: ^/
                provider: entity_searchers
                anonymous: ~
                form_login:
                    check_path: /searchers/login_check
                    login_path: /searchers/login
                    default_target_path: /searchers/
                logout:
                    path:   /searchers/logout
                    target: /searchers/login

but I want this not to infulence the --> site.com/crm I understand the the patter is regex but could not solve it.

I'm not very experienced with Symfony nor its firewall, but regex-wise this should work provided the regex engine supports negative lookahead:

pattern: ^/(?!crm)

http://regexr.com?35efu