heres a working example of a proximity..
	Code:
	sub EVENT_SPAWN
{
	$x = $npc->GetX();
	$y = $npc->GetY();
	$z = $npc->GetZ();
	quest::set_proximity($x - 20, $x + 20, $y - 8, $y + 8, $z - 15, $z + 50);
}
sub EVENT_ENTER
{
quest::movepc(34,-780,2120,5);
}
 quest::set_proximity(minx,maxx,miny,maxy,miz,maxz) is what it is so you have to specify the exact locs you can even just make it like..
quest::set_proximity(200,-200,100,-100,10,-10);
this would make a proximity at those same coords.
hope this makes sense and helps 
 
edit: yours is probably working but you have to go to the coords 0,30