to create the file ldappass.htm in the docs directory, then use an LDAP entry like this: 

::LDAP
PasswordForm ldappass.htm
BindUser CN=ezproxy,CN=users,DC=yourlib,DC=org
BindPassword verysecret
URL ldaps://ldapserv.yourlib.org/CN=users,DC=yourlib,DC=org?sAMAccountName?sub?(objectClass=person)
Expired; Deny expired.htm
/LDAP