Unable to spy on Microsoft.Windows.ShellExperienceHost Process

I have a Desktop application which generates a notification near the system tray. I want to capture the message displayed inside the notification. When I spy on it I get the Full Name as below:

Sys.Process("Microsoft.Windows.ShellExperienceHost").Window("Windows.UI.Core.CoreWindow", "New notification", 1)

How to access the objects inside this?