[Samba] using UPN instead of samaccountname with winbind

[Terry]

Hello,

I have winbind authentication working my a win2003 AD, however, I have
to authenticate using DOMAIN+samaccountname right now.   I would
prefer to use the UPN.  The UPN in my case is their full email address
username at domain.com.   The context for this authentication could be
anything that pam supports. How can this be done?   I am using
samba-3.0.28 on Centos 5.

Thanks!
Terry