Would it be possible to have a Masteritem submenu on the right's editor expression (like variable). It would be easier to select a masteritem instead of to script them.
NOTE: Upon clicking this link 2 tabs may open - please feel free to close the one with a login page. If you only see 1 tab with the login page, please try clicking this link first: Authenticate me! then try the link above again. Ensure pop-up blocker is off.