The tutorial I linked will show how to add the context menus.
Whatever is in Folder "0", labeled as "Play" is what it will launch when you double click the icon from game Explorer.
You need to delete the Play shortcut, replace it with the app you want to launch, and name it Play.
The folders 1 and up will be options.
Once you do all the steps in the tutorial Brink Linked, you can then edit these things. remember, Folder 0 must be labeled as "Play" , regardless what shortcut you put there.
To have the app always prompt for Admin privlage, simply navigate to its main location.
Right Click the exe you want to runas Admin, choose Compatability, and check the "Run this program" as Admin box.