(Backup xmlns="http://schemas.microsoft.com/analysisservices/2003/engine")
(Object)
(DatabaseID)POM(/DatabaseID)
(/Object)
(File)C:\PO.abf(/File)
(/Backup)
Above query will help you in doing it. You need to replace ( with Angular Bracket and ) with closing Angular Bracket
P.S. I could not write proper query as Angular bracket is being considered as HTML tag 🙁