set LogFileSet = GetObject("winmgmts:{impersonationLevel=impersonate,(Backup)}").ExecQuery("select * from Win32_NTEventLogFile where LogfileName='Application'")

 

For each Logfile in LogFileSet

                RetVal = LogFile.BackupEventlog("c:\BACKUP.LOG")

                if RetVal = 0 then WScript.Echo "Log Backed Up"

                RetVal = LogFile.ClearEventlog()

                if RetVal = 0 then WScript.Echo "Log Cleared"

Next