How do you test a WPF application for partial-trust problems?

We have a WPF application that a client had trouble running (the file-open dialog windows would not show), that we narrowed down to being a partial-trust problem from being run from a network folder.

How do I tell QA the steps to test a regular WPF application that ensures that our partial-trust fix is working correctly? Is there a bit or flag you can set on the exe properties that forces it to partial-trust (without recompiling the application)?

Thanks, Brian