[exim] Special routers questions

Hi

I've the follow routers configuration for local domain

special:
  driver = manualroute
  transport = remote_smtp
  route_list = arthis.it srv-mail01 ; \
               gcispa.com srv-mail01 ; \
               rinascente.cc srv-mail01 ; \
               fax.rinascente.cc corp_link1

I need to send mails for the domain fax.rinascente.cc to corp_link1, if the
routing fail I wont that mails go to corp_link2

I can't find how to make it.

Andrea