First of all, if you need to get your data from SQL Server, you can simply use the sql statement as is and let SQL Server simply return the results to Qlikview.
This below puts the burden on Qlikview loading all records from Incident with the second select:
Select ProfileFullName, Subject
group by Subject,ProfileFullName
having COUNT(Subject) > 1;
Select ProfileFullName, Subject,IncidentNumber
Personally I'd let SQL Server do the work. That's a lot less data that has to be thrown over the net to Qlikview.