Raspbian Stretch does not have a "lock screen" applet which I can add to the panel. (At least I have not found one.) After some research I found and installed the xsceensaver package. "xscreensaver-command -lock" will do what I desire. I added it to the main menu and can invoke it from the menu. However, I cannot move it from the menu to the application launcher area of the panel.
The Application Launch Bar properties dialog allows me to select an "installed application." However, my hand made entry on the menu does not show up as an installed application. Any suggestions?
If I have to leave the the lock screen entry on the menu I would like to move it from "Applications" to the top level of the menu - where Shutdown is located. I do not see a way to do this either.
TIA,
Ken