Help with CATIA Coding

Hi, does anyone know how to access the user reference properties using selection? I can access system properties simple enough, however the same code doesn't seem to work for user reference properties.

I'm using something along the lines of

CATIA.Activedocument.Selection.Item(1).Value.Name

This will recall what is populated in system properties, however I want to be able to recall what is in user defined properties.