That would require some scripting but a trick you could use would be.
(1) place an entity down and set spawn on start to no
(2) now set the maximum spawn to 1 and number to spawn also to 1
(3) set the name to something that you would remember, maybe something like "waypoint1"
(5) now place a trigger zone down and put in the if used to "waypoint1" or whatever name you chose
This should work I just don't have time to try it right now.
Note this will make the character appear and not just all of a sudden follow a waypoint. the character will have to start behind a wall for the player not to see the trick you just did
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