Is Active Directory's ExtensionAttributes9 a field in user object and how to retrieve it in the class type userprincipal?

Question

Hi, I'm using VS2012.
I want to use this ExtensionAttributes9 field to store date value for each user object.  I use UserPrincipal class, a collection of these objects are then bind to a gridview control.  Is ExtensionAttributes9 a field in AD user object? 
How can I access it and bind to the gridview?
If this field isn't available then what other field can use?
Thank you.
Thank you

Answer 1

UserPrincipal is basically a wrapper around DirectoryEntry:
http://msdn.microsoft.com/en-us/library/system.directoryservices.directoryentry.aspx and only provides a subset of the Active Directory, although the most common, attributes that are available for the user object.  The attribute that you
seek is not one of them.
By utilizing the method that I provided you a link to, it will return the underlying DirectoryEntry that was used to build the UserPrincipal object and should allow you to access the attribute that you seek.
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