I'm a noob at Applescript, but managed to get the first half of this script to just display the menu. The image is a mouse hover to display the UI Browser result. The syntax for clicking on a menu with a long number instead of a name eluded all my searching. Perhaps a Relative Specifier could work for that specific menu item?
tell application "System Events"
tell process "Remote Desktop Scanner"
tell menu bar 2
click menu bar item 1
click menu item 2 of "menu -9223372036854775808" (this bit failed)
end tell
end tell
end tell

-9223372036854775808looks like a bug somewhere, it's0x0x8000000000000000."menu -9223372036854775808"is a string. Tryclick menu item 4 of menu 1.menus of menu bar 2? Andmenus of menu bar 1for that matter?delay 0.5to wait for the menu.