Return Labels - Manually Print problem

In my shiprush settings, there are three options for return labels. Off, Automatic, and Manual (print when CTRL-F10 is pressed). I can get a return label to print automatically with every shipment, however, this is not needed. When I press CTRL-F10 before creating a shipping label, a shipping label is printed, not a return label. If I press CTRL-F10 after a shipping label has been printed, nothing happens. How to I print a return label only when I need one without going into settings and changing it to Auto and Off every time??