[otrs] limit on Customer features

Hi list, I've just intalled and started playing aroud with OTRS. I'm wondering whether it is positble to restrict wich queue a customer can place a ticket. I mean: I've created 2 queues called Q1 and Q2, and I've 2 customer called C1 and C2. I want C1 to post requests only on queue Q1 and I want C2 to post on Q1 and Q2. I've been checking Customer modification form and I don't see such a feature. I should work somehow like it works with users.