i'd suggest placing him inside just before the balcony, point him in exactly the right direction, and at the appropriate time, tell him to
loon_name playmove "CivilWalkF"
you'll have to play with the distance from the balcony so he doesn't walk right through it, but that's as close as you're going to get without setposing the loon into place.
i have an outro which uses the same balcony. the way i did it was to put an empty marker at the balcony's position, and then setpos the loon to the appropriate height which waaaas - bedges hunts for the outro - 8.4
of course there was no movement involved, the camera only saw him after he was there.
you'll find there's also a slight lip to the door meaning the loon may appear to be floating if seen from inside. seen from outside is no problem.