[Dovecot] moving from postfix+dovecot to postfix+dovecot+postfixadmin+mysql

hi,

i know this is not really a dovecot-question, but (after searching for hours and hours) here goes :

last week i've tested a setup with postfixadmin and dovecot, and i'm very happy with the result!

it's running on a FreeBSD-server but i've used this howto (which describes the setup for debian) :

http://bliki.rimuhosting.com/space/knowledgebase/linux/mail/postfixadmin+on+...

big question is :

how can i convert the already existing passwords from the mail-users to the mysql-based auth in postfixadmin/dovecot

thanks for having dovecot available, it's great to work with ! :)

-- grtjs, albi gpg-key: lynx -dump http://scii.nl/~albi/gpg.asc | gpg --import