samba - Apr 2006 - prepopulate winbind db with certain uid <-> SID mappings?

Hi,

when migrating a big linux/samba fileserver with several hundred local 
users/uids and more than a million files to a winbind/Windows AD setup, 
it's not desirable to have new uids assigned for all the users from a 
uid range by winbindd, because the file ownerships are messed up then.

Is it possible to keep the original local uids for already existing 
users with winbind even after these users have been deleted from 
/etc/passwd?

(I know that the idmap backend "ad" offers this for a AD/SFU (Services
for Unix) environment, but this solution doesn't do a real uid <-> SID
translation and forces me to maintain Windows and Posix group 
memberships seperately on the DC.)

Thanks for your support!

Christoph