What is the role of "alumnae panhellenic"?

[GreekFreak]

What is the role of alumnae panhellenic (for NPC sororities) in the cities where it exists?

I know alum members are often contacted by their local alumnae groups where they live for various events, but are there ever times when someone could be contacted by alumnae panhellenic for all-panhellenic events? Do alumnae panhellenics ever say, "Let's get all the Zetas and Kappas and Pi Phis, etc. together within a 100-mile radius of Metropolis and do something social."

Does alumnae panhellenic have a database of all the members from various NPC groups that live in a particular city or region within a certain mile radius, for purposes like I described above?

Obviously all NPC groups keep a detailed list of their members, but since they're all under the umbrella organization of NPC, does NPC have access to all the 26-member lists/database too?

I'm curious because I've lived in a couple of large U.S. cities and have never been contacted by alumnae panhellenic to participate in events with other Greeks from different affiliations, but I have heard of such events. Or are such events for panhellenic delegates only? Maybe I'm just confused...

Hope this makes sense!