DevXpress TreeList - accessing node during Drag&Drop

I’m trying to access node in DevXpress TreeList during Drag&Drop, but getting Undefined on CalcHitInfo()
I would like to recieve some data about the node when user hover over it, mainly to filter possibility to drop the item on the item under.
Does anybody have experience with this, please?

Code sample:

rollout tltest "XtraTreeList Test" width: 500 height: 200
    dotNetControl tl "DevExpress.XtraTreeList.TreeList" width: 450 height: 180
	on tltest open do (
		tl.OptionsBehavior.DragNodes = true
		tl.OptionsBehavior.editable = false
		tl.DragNodesMode = tl.DragNodesMode.Advanced
		col = tl.Columns.Add()
		col.visible = true
		tl.Columns.item[0].Fixed = tl.Columns.item[0].Fixed.Left
		n0 = tl.AppendNode #("green") -1
		n1 = tl.AppendNode #("blue") -1
		n2 = tl.AppendNode #("gold") -1
	on tl DragOver arg do (
		p = dotNetObject "System.Drawing.Point" arg.x arg.y
		TheNode = (tl.CalcHitInfo p).Node
		print TheNode
createdialog tltest

The correct code is (fix) …

p = tl.PointToClient (dotNetObject "System.Drawing.Point" arg.x arg.y)