[Dovecot] How can I integrate change_password plugin, dovecot and postfix

[Yavuz Maşlak]

 Hello

 I use dovecot, postfix, mysql and squirrelmail as a mail server. it works 
 well. Meanwhile I am novice at postfix.
 As you know, there is a change_password plugin on squirrelmail.
 I wish to add change_password plugin on squirrelmail.
 I couldn't find how to integrate postfix and change_password.
 How can I add it ?