Hi i am writing and add in for VS.NET 2003 and i have 2 questions

1.I am looking for a sample in C# for creating custom editor
  for custom file type in VS.NET

2.I want to know if it is possible to open a custom editor(not the
same from first question)
using the context menu when right click on a class in the class view
explorer,
(i know how to add a menu and handle events,i dont know how to open an
editor)
for example i would like to dipslay a UML diagram for the class

thanks