Steve, maybe I'm mistaken but the feature is almost the same as the one described here http://docs.jboss.org/hibernate/core/3.3/reference/en/html/queryhql.html#queryhql-tuple
Probably the missing bit is the ability of Hibernate to construct the " ('a','b') " part of the query from a list of object arrays.
The porkarround I have adopted is to construct the string " ('a','b') " from the list and to replace the token ":pairsList" before creating the query.
Thank you.