Interface Containment

Hello, I would like to create an ATL server that contains interfaces within interfaces, such that I can provide a hierarchy of methods much the same way it's done with Excel and other MS products. For example, suppose I have a COM object interface named ICAR, some of the methods allow me to Drive the car, or steer the car, or turn on the lights. I also might have an Object named IEngine - this object has methods for checking the oil level, the temperature, and so on. I would like to expose both of these interfaces, ICAR and IEngine, but I would also like to expose the Interface (and methods) for IEngine from within ICAR, such that I could call the get temperature method as follows:

currentTemp = myCar.Engine.Temperature

Any help on this would greatly be appreciated.