why cannot use Chinese character in nnmail-split-methods

[haomiao]

Hi

         I want to split my mails through  nnmail-split-methods
setting. When I use regexp all in English, everything is fine, but
when I use regexp having some Chinese charaters, the mail will not be
split into the right mail folder.
         Why this happened? How to resolve it?

         Here is my code in .gnus.el
----------------------------------------------------------------------------
(setq nnmail-split-methods
      '(("Mail.test" "^Subject:.*\\(测试\\|test\\).*")
        ("Mail.inbox" "")))
----------------------------------------------------------------------------

         Thanks.