[exim] acl variables, a little problem

I need to configure Exim to quarantine emails that have media
attachments over 1.5MB that do not also have PDF or DOC attachments.

In the mime acl, there is this...

  # This variable set to 1 means skip large size limit test
         warn    set acl_m6 = 0

         # This variable set to 1 means the email attachment is large 
size multimedia
         warn    set acl_m7 = 0

         # Pretty good attachments that we can skip size limits
         accept  condition = ${if 
match{${lc:$mime_filename}}{\N(?>.*)(?<=pdf|doc)$\N}{1}{0}}
                 set acl_m6 = 1

         # Quarantine media greater than 1.5 MB
         warn    condition = ${if >{$message_size}{1536k}{1}{0}}
                 condition = ${if 
match{${lc:$mime_filename}}{\N^(?>.*)(?<=jpg|jpeg|pps|ppt|gif|png|wmv|mpg|mp3|mpeg|avi|wav|bmp|mov|asf|asx)\N}{1}{0}}
                 set acl_m7 = 1

In the routers, there is this one....

# Email with large media attachment are quarantined
large_media:
    driver = accept
    condition = ${if and { \
         { eq{$acl_m6}{0}{1}} \
         { eq{$acl_m7}{1}{1}} \
         {! def:h_X-MedQuar:} \
         }{1}{0}}
    headers_add = X-MedQuar: True
    transport = large_media_mail

This router is bypassed completely. Aren't acl variables available
during router time?

Thanks,
Craig Jackson