RMAIL reply headers

[DJ Delorie]

Emacs 23.2.1, Fedora 13

When replying to an RMAIL mail, how do I do the following to the
pre-filled-in headers?

* I want "To" listed before "CC" (adding a new cc inserts CC after To,
  but a pre-filled in one does not).

* I want to filter duplicates out of the address list (and potentially
  a custom elisp filter for what a "duplicate" is, i.e. alternate
  spellings of host names).