sieve/vacation From line?

[andrew.caird at fccc.edu]

Hello,
  I'd like to be able to set the From line on sieve/vacation replies by
hand.  For historical reasons, people's login IDs do not equal people's
email addresses, and sieve/vacation simply replies as the mailbox name (in
my case "acaird at fccc.edu"), but in general that address isn't valid, and
it should reply as "andrew.caird at fccc.edu".
  I was really hoping that vacation would take a ":from" parameter, but it
doesn't seem to.
  Thank you.
--
Andrew Caird