[exim] How to convert userforward setting from exim3

Hi,

I just upgrade my exim from 3.36 to 4.63 under debian. One problem I have
userforward settings. In Exim3, I have follow settings:

#     This catches emails such as test.group@???
#     and drops them into mygroups@???
mygroups:
  driver = smartuser
  new_address = mygroups@???
  # no_verify_recipient
  no_verify_sender
  suffix = ".*"

How can I make this working under Exim4?

Cheers,

Tao