lpr User Authentication (undocumented option -U)

Environment:
cups-1.1.18
samba-2.2.8a

I recently found that lpr supports an option -U that can be used to 
change the job originating user. As I use an accounting system, that 
causes some difficulties to me ...
I read about authentication in cups. The only solution I found is to 
modify cupsd.conf so that a username and password is required in the 
/printers-section -- but then it is required for every access to any 
printer: lpr job requiers a password, lpq -Pprinter requires a password 
and so on. I don't think this is very sufficent for our users.
Assuming I will accept these permanent password inputs: What with samba? 
Are jobs sent to cups via samba authenticated automatically with the 
user and password of the job originating windows user? Escpecially if I 
use a self defined print command?

Any help is appreciated, thanks in advance
--
Regards
Christoph
________________________________________________________________________
Christoph Litauer                  
litauer-82PuzOe0+4+KVelC9LqlCA@xxxxxxxxxxxxxxxx
Uni Koblenz, Computing Center,     http://www.uni-koblenz.de/~litauer
Postfach 201602, 56016 Koblenz     Fon: +49 261 287-1311, Fax: -100 1311
PGP-Key: http://www.uni-koblenz.de/~litauer/public-key.html