After research here and there at last I reached to my destination and able to update the AD password to the server.
Most important thing is that you have to use ldaps:// instead of ldap:// only then server will allow ldap_mod_replace function to update the user's password to the server database where Active Directory installed.
I have created a plugin which is extension of the active-directory-integration this plugin (url:http://wordpress.org/extend/plugins/active-directory-integration/), means my plugin using the server details provided by the admin through this plugin. But as I have created this plugin on client request I cant share this.
But any kind of help regarding this please feel free to contact me at firstname.lastname@example.org