and thanks for quick reply :)
Now I know that CampTix is compatible with WPMS, I didn't tried yet but good to know.
Anyway WPMS isn't the scenario about what I tought asking for this feature.
What I would like to see is capability to manage multiple events between the same site, not each separate event and I explain one typical case: a school that organizes courses and for each course need to manage attendees, tickets and so on, all Camptix already does.
What need, in this case, it's the ability to set multiple events in option page or, may be, ability to assign them to custom posts types like calendar ones.
Hope that it's more clear now :)