Samba print jobs

[Vieri]

I have a printer connected to a Gentoo Samba print server. Several Windows clients with AD-authenticated users send their print jobs to the Gentoo Samba machine.

All's fine except that I need to force user re-validation of the print jobs, as to company policies.
I need to force users to physically go to the Gentoo Samba machine and enter their credentials so that the printer right next to it starts printing out their documents.
It's a bit redundant because their Windows clients have already authenticated via AD but it's an extra security measure...

So the Gentoo machine would have to be setup this way:

1- accept Samba print jobs for AD-authenticated users but put them "on-hold" (paused)
2- do a custom-made GUI application on the Gentoo machine that simply asks for user name and password (AD) and if correct, then un-pauses the user's print jobs.

Is there an easy way to do this?

Thanks,

Vieri