Though it has been few versions since MyEclipse had support for Hibernate and HQL, I only had a chance to play with it recently. It has a nice feature set and the HQL editor is tied Dynamic Query Translator which gives on-the-fly translation for HQL queries. This provides for an easy way to debug queries and validate them.
In order to open a HQL editor you need to create a file with .hql extension and also have an active hibernate configuration file. This took me a while to figure out. In order create an active Hibernate Configuration use File -> New -> Hibernate Configuration File and setup the connection parameters for the database.