New object with HQL

I think that the section 15.6. The select clause covers what you're trying to achieve:

15.6. The select clause

...

Queries can return multiple objects and/or properties as an array of type Object[]:

select mother, offspr, mate.name
from DomesticCat as mother
    inner join mother.mate as mate
    left outer join mother.kittens as offspr

Or as a List:

select new list(mother, offspr, mate.name)
from DomesticCat as mother
    inner join mother.mate as mate
    left outer join mother.kittens as offspr

Or - assuming that the class Family has an appropriate constructor - as an actual typesafe Java object:

select new Family(mother, mate, offspr)
from DomesticCat as mother
    join mother.mate as mate
    left join mother.kittens as offspr

In your case, you probably want:

SELECT new MyCustomList(product.code, SUM(product.price), COUNT(product.code))
from Product AS product
GROUP BY product.code

Where MyCustomList is not necessarily a mapped entity.

I know that this is an old post, but you can also use for HQL:

Query query = session.createQuery("SELECT code AS code FROM Product"); 

or this for SQL:

Query query = session.createSQLQuery("SELECT code AS code FROM Product");

with:

query.setResultTransformer(Transformers.aliasToBean(MyCustomList.class));