How To Create Custom Reports in Servicedesl Plus

How To Create Custom Reports in Servicedesl Plus

Dear All
 
I would like to create the following Reports in Servicedesk Plus:
 
- unresolved Service Request for more than 2 weeks for medium priority
- unresolved Service Request for more than 3 working day for high priority
- unresolved Service Request for more than one month for any priority

 
 
Any One have an Idea to do that?