[EXIM] match-string in filters

I want to delete spam-mails, especially mails with strings such as

       $ 100 billions
in the body.
The pcretest utility says 'match' with
   re> "\$\s*\d+\s+[mb]illion"
and
   data> $ 100 billion

In the filter-file is the condition

if $message_body matches \$\s*\d+\s+[mb]illion or

(followed by other conditions)
But a mail with
$ 100 billions
is not discarded (no match). But if I correct the condition to

if $message_body matches \\$\s*\d+\s+[mb]illion or

I get

     Filter error: failed to expand "$\s*\d+\s+[mb]illion" in filter file:
$ not followed by letter, digit, or {

I believe that in the first case of the condition (one backslash) the $ is
interpreted as end-of-line (the condition string isn't correct
transferred to the pcre-interpretation-routine).

I would thank you for comments.

Rudolf

-- 
-----------------------------------------------------------------------
Rudolf Kompf                     | E-mail: kompf@???

--
*** Exim information can be found at http://www.exim.org/ ***