"User must change password at next logon" is checked and the user can not logon.

Ok, here is my scenario.  I have the option in Active Directory where the checkbox for "User must change password at next logon" is checked and the user can not logon.  What I would like to be able to do is to capture the status code from active directory that states that and thereby fork the user to the change password page.  I would appreciate any assistance that can be offered here.  Here is my login.aspx page source code.  I wound up not being able to use code-behind so I locked all the code into the page header.   I'm going to just give you the goods.
<%@ Page language=" ...