Sets a pointer to the list-box item
[C++]
int SetItemDataPtr(
   int nIndex,
   void* dwItemData
);
Specifies the zero-based index of the item in the list box.
Specifies the pointer to be associated with the item.
-1 if an error occurs.
Sets the 32-bit value associated with the specified item in a list box to be 
			the specified pointer (void*). This pointer remains valid for the life of 
			the list box, even though the items relative position within the list box might 
			change as items are added or removed. Hence, the items index within the box can 
			change, but the pointer remains reliable.
Header: xldialog.h