Archive Send Messages To More Than One Group

[narke]

i currently use the following code to save my send mail messages back to the
inbox(nnml:mail.misc), so i got a more news group feels for my mail group.

(setq gnus-message-archive-group
      '((if (message-news-p)
            "nnml:send-news"
          "nnml:mail.misc")))

but, now i plan to split the inbox into to group, one is nnmail:mail.misc
another is nnml:mail.friends. the code is below,

(setq nnmail-split-methods 'nnmail-split-fancy
      nnmail-split-fancy
     `(|
       (from "myfriends@somewhere" "mail.friends")
       "mail.misc"))

so i want to change my archive method in such a way that any mail posted in
mail.misc will be saved to mail.misc and any mail posted on mail.friends will
be saved to mail.friends.  to achieve that, how do i modify the
gnus-message-archive-group code?

thanks.

-
narke