Check cc user in external database?

Running RT 3.0.2 pre6. So far everything works exactly how we want it to
except one thing. Is there a way to make sure people added on the
cc/admincc line are in an external database (LDAP)? We don’t want typos &
extra users showing up in the rt3 database. I have
$LookupSenderInExternalDatabase and $SenderMustExistInExternalDatabase set
and working great for the creation of new tickets.

I tried to find where cc’s & admincc’s get added in the code so I could
make it use the LDAP lookup code, but couldn’t track it down.

Thanks for any help!

– Jeff Hoover