Hi,

I have a newbie question about HQL.
...
...
- I'm terribly sorry if I'm wasting your time by missing something totally obvious!

Right. I found the answer in "Java Persistence with Hibernate" (14.3.3).
Evidently subselects are only supported in the WHERE clause...

Sorry to bother you all!
I'll stick with the session.createSQLQuery() solution.
No, hey! got it!:

MyMappedClass anObject = new MyMappedClass();
Query q = session.createQuery("select functionB( functionA(resultX) ) from MyMappedClass as resultX where resultX = :myObject");
q.setParameter("myObject", anObject);

Dunno why I didn't think of this before...