I made this with respawn a few months ago

Nah, I don't need them to respawn. I need them to go to specific location when, say, player inside trigger_multiple. I know how to make everything work except make zombies go where needed.
create_zombie_point_of_interest() function seems rather glitchy.

Just create a point of interest at the triggers origin. Set the radius less than the distance you are teleporting them too. If they get inside the distance it will mess them up without a path to it. Then when they trigger the trigger, teleport them.

But the effect will be permanent? No way to make them path to players again?

	dest = getstruct(self.target,"targetname");//target of the trigger multiple, self
	zombie forceTeleport( dest.origin, dest.angles );
	while(distance(zombie.origin,dest.origin)>10){
		wait(.01);
	}
	wait(.5);
	zombie.ignoreall = false;
	zombie thread maps\_zombiemode_spawner::set_zombie_run_cycle();