It is often easier to develop a query using the Ad-Hoc query tool and then when finished, copy the query to reporting or any other area using queries such as Recipient Groups.
To copy a query between areas, you can use the provided copy and paste buttons. The only requirement in the destination location is that you pre-select the same schema as you are using in for the query being pasted.
The copy/paste buttons are located as shown below:
in Ad-Hoc Queries
In Reports & Recipient Groups - on the Query Criteria Screen