Kuwait Salesforce Admins

I wanted to write a validation rule on Opportunity such that two profiles let say Global Elite User(ABC) and GLobal Finance User(EFG) should be able to change the Opportunity Stage (Picklist) if it is in the WON stage to LOST, CANCELLED, or IMPACT or IDEA or WIP, and IF Stage is equal to LOST, CANCELLED or IMPACT No One should be able to change the record. Another condition is if Stage is equal to IDEA or WIP a Global Sales Profile(QWE) as well as Global Elite User(ABC) and GLobal Finance User(EFG) should be able to change it to the WON stage but once it is in the WON stage Global Sales Profile should not be able to change it back to IDEA or WIP but Global Elite User(ABC) and GLobal Finance User(EFG) should be. @Steve Molis @Eric Praud  @Eric Schubert