How do I reorder the programs in the 'open with' window of a file? I want to reorder (not change the default program) the programs suggested in the menu when I click on 'open with' for a file. 

Is that possible, if yes, how?
Unless someone comes up with some heavy magic, I'm going to say: "No". Apple lists the apps that can open that file type in alphabetical order. (Higher versions of the same app are listed first.)