Query Expression: Using an aggregate in a CASE statement

Hi All, I'm trying to create a query with the PeopleSoft Query Builder tool that tells the user if someone has adequate role security access to function properly within PeopleSoft. The query uses an aggregate expression to count the number of roles a user has (included as a column in the query). If the user has the maximum number of roles required, the query should display message 1: "PS Security is sufficient". Anything less than the max number of rows should show message 2: "Security Update Required".