"How can pointers be explained using only concepts that are familiar to a .NET or Java developer? "
I'd suggest that there are really two distinct things that need to be learnt.
The first is how to use pointers, and heap allocated memory, to solve specific problems. With an appropriate style, using shared_ptr<> for example, this can be done in a manner analogous to that of Java. A shared_ptr<> has a lot in common with a Java object handle.
Secondly, however, I would suggest that pointers in general are a fundamentally lower level concept that Java, and to a lesser extent C#, deliberately hides. To program in C++ without moving to that level will guarantee a host of problems. You need to think in terms of the underlying memory layout and think of pointers as literally pointers to specific pieces of storage.
To attempt to understand this lower level in terms of higher concepts would be an odd path to take.
