In Google Maps, when you right click on a map spot, the first line of the context menu is the coordinates in decimal format. Click that line and you should get a notification at the bottom of the screen that the coordinates have been copied to your system clipboard. From there, go back to the sim’s world map and locate the search blank on the left side. Click there once, then use Ctrl+V to paste in the coordinates. If you already have a start and end point set, you can add that spot as a waypoint. You can also set it as a start or end.