Have you tried using the ListStaticsAtLocation function?
Assuming you are character, and because there can be more than 1 item on your square, you can do something like:
Code:
foreach static in ListStaticsAtLocation(character.x, character.y, character.z, ITEMS_IGNORE_MULTIS, character.realm)
var value := static.objtype
if ( static.z == character.z )
// this is a tile the player is on at the same height ......... do stuff
endif
endforeach