Modify Panelview Plus screens without original application

I have been asked to modify a few Panelview Plus 6 screens, to add extra funcionality.

The owner doesn't have access to the original developers code.

Is it possible to upload the code from the screen and then modify this in Factory Talk View Studio?

If the application was written in V5 or newer, there is the possibility that the MER can be restored as long as the original developer didn't disable it. Upload it from the PanelView and try to restore it from the Application Manager (Restore runtime application).

You can check the version of it if you want with this:

http://www.plctalk.net/qanda/showthread.php?t=90986