Hibernate 3

I have a top-level interface called OrderProcess.
This interface is sub-classed into JaraOrderProcess (and more to come)
The latter interface is implemented by one (more to come) class.

I wanted to use the approach table per subclass using a discriminator for defining the first level of inheritance, and table per class-hierarcy for the second level.

My primary table should then contain data common for all OrderProcesses (plus the discriminator) , and the subclass-table should contain data for all implementations and the discriminator for selecting the concrete class.

What would be the right approach to achieve this ?