splitting to different groups according spam level

[Ronan KERYELL <Ronan.Keryell@lit.enstb.org>]

I use spamassassin and I have a working nnmail-split-fancy with a rule
("x-spam-flag" "YES" "mail.SPAM")

that triggers at spam level 5.

Now I would like to split lower spams according to their spam level that
also is represented by the star number in the x-spam-level header such as
:
X-Spam-Level: **


Unfortunately I have not succeeded to write a matching rule for that.
I've tried those mutating regex but none is working :-/
setq nnmail-split-fancy
 '(|
   ;; A message inherit the group of its parent if any :
   (: nnmail-split-fancy-with-parent)
   ;; The first match wins :
   (|
    ;; The SPAM from level 2 :
    ("x-spam-flag" "YES" "mail.SPAM") ;; this one works
    ("x-spam-level" "\\*\\*\\*\\*" "mail.SPAM.4")
    ("x-spam-level" "\*\*\*" "mail.SPAM.3")
    ("x-spam-level" "**" "mail.SPAM.2")
    ("x-spam-level" "\\\\*" "mail.SPAM.1")
[...]

Any idea ?

Thanks,
-- 
  Ronan KERYELL               |\/  Tel:    (+33|0) 2.29.00.14.15
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