samba password and read only attributes

I' m using this module in an big integrated environment. The problem is i want to allow users to change its proper passwords, on the other hand i don't want allow then to update the email field.
I developed an ugly code (2:20 AM) that works.
the patch allows to change the samba passwords too. the sambaLMPassword and sambaNTPassword fields are generated via mkntpwd and updates during ldap password change;