Here's an easy way to get the index of a subitem clicked in a dot net list view

--lv is the DotNetListView object
 fn subItemAtMousePos =
 (
  	pos = lv.mousePosition -- screen position 
  	pos = lv.PointToClient pos -- position in listview window

  	li = lv.getItemAt pos.x pos.y

  	si = li.getSubItemAt pos.x pos.y 
  	#( li.index , (li.subitems.indexof si) )
 ),
    
 on lv click arg do
 (
  	theCell = subItemAtMousePos() 
  	format "cell index X: % Y: %" theCell[1] theCell[2]
 )