[exim] Block UTF-8 subject header

Hi,


I've got a filter against mails with subjects looks like below:

    deny    senders         = *
                message         = Blocked due to unwanted subject line.
                condition       = ${if
and{{def:header_subject:}{match{$header_subject:}{${readfile{/etc/exim4/subjects_reject}{|}}(?!)}}}{1}{0}}
                log_message     = Blocked by unwanted subject line
(subject=$h_subject:)

But that filter doesn't read subject coded in utf8. Is there any method
to rebuild above filter that blocked mail with uth8 subjects?


Regards