New Post: Custom frame editor for a collection property

In XAML, if I add TreeView and look at its properties in the Property Editor window I will see an Items property of type (Collection) followed by a [...] button that can be clicked to display the Collection Editor.

Now in MPF I find I can do the same thing if my NodeProperties has a property like so:

[LocDisplayName("Things")]
public List<int> Things { get; set; } 

Visual Studio will show the [...] in the Property window and when clicked shows the same Editor as before.

My question is: can I create my own form/editor that will be displayed when the [...] is clicked for more complex property types. I don't want the standard Collection Editor.

e.g.

[LocDisplayName("People")]
public List<People> People { get; set; } 

class People {...}

Is there a COM interface that I should be looking at?