How do I move a window vertically above the menu bar?

How can I move a window so that the title bar of the window is above the menu bar?

I've tried using AppleScript…

tell application "System Events" to tell process "System Preferences"
    set position of windows to {-100, -100}
end tell

…and whilst the x variable works, moving the window partially off-screen, the y doesn't, moving the window up to the menu bar and no further.

I've also tried Keyboard Maestro:

…but have the same problem: the x value works but the y does not.

^{This question is related, but opposite: How do I move a window whose title bar is off-screen?
I want to be able to cause the title bar to be off-screen.}

Finder does not allow this as a general rule. Sometimes a glitch can make this possible, but relaunching Finder usually rectifies it. There's currently no known way to actually get this to happen as a desired behavior, sorry.

Not really an answer, more a 'don't try this, it doesn't work'

... one thing not to do is try changing which of 2 screens ought to have the menu bar - unless you want to spend 10 minutes putting all your windows back in the right place