Samba PDC function

Hiya all! I'll try this question once more... I'm about to use the Samba server as a Windows PDC and it seems to work perfectly well (not surprisingly).. But I miss a function, or perhaps I've simply overlooked it somewhere. I'd like to be able to set some login restrictions based on time. For example users in the "sales" group should only be allowed to login between 7am and 6pm weekdays. Is it possible to achieve this via the Samba server? Thanks! Anders Norrbring