Switching Virtual Terminals on Linux using ctrl alt Fn

I'm using a linux guest on a linux host and there appears to be no way to switch back to VTY7 other than rebooting. I can send ctrl-alt-f1 or f2 via the Devices menu but there appears to be no documented way of configuring extra modifiers or keyboard shortcuts. Can anyone help?

 

In the keyboard settings, you can also make your keyboard use the F* keys, instead of the function keys (like launchpad and mission control), but this still isn't a good solution, since it also affects those functions outside of the Linux box; so you'd have to change it back all the time. I'm looking for a better solution, myself.