[exim] Running mysql query

Hi all;

I in need to run one mysql query when user recieves a mail.
But i dont have any clue where or how to run it.

Here is the transport part:

virtual_delivery:
driver = appendfile
file = /var/spool/mail/${lookup mysql {MYSQL_Q_BOXNAME}{$value}}
user = Debian-exim
group = mail
mode = 0660
directory_mode = 0770
MYSQL_QUERY


and router:

virtual_mailbox:
driver = accept
domains = ${lookup mysql {MYSQL_Q_LOCAL}{$value}}
transport = virtual_local_md_delivery


Im thinking of putting the command to transport part but dont know how.
Any help would be nice.

Best regards,
Juuso