Hi,
I'm not exactly sure about the use case, but you can add Xdata to an entity, Xdata has a special code for handles (1005 if I recall well) and if that entity get involved in a nesting process, like a block or array, you can explode in memory that complex object, and search for the handle stored in the original object/entity. In .NET you can do that (explode the complex object) inside a not committed transaction.
Gaston Nunez