You can have the Win32Shutdown method shut down a computer by changing:
oOperatingSystem.Win32Shutdown(WIN32SHUTDOWN_REBOOT | WIN32SHUTDOWN_FORCE) to oOperatingSystem.Win32Shutdown(WIN32SHUTDOWN_SHUTDOWN | WIN32SHUTDOWN_FORCE) or oOperatingSystem.Win32Shutdown(WIN32SHUTDOWN_SHUTDOWN_AND_POWER_OFF | WIN32SHUTDOWN_FORCE).
I doubt you could use this in a WoL environment as WMI requires Windows to be running. Documentation of the Win32_Operating system class is on Microsoft's web site: Win32_OperatingSystem Class.
What sort of problem are you having with the action, Manuel?
You'll be able to do this if you create a separate device and assign just this monitor to it, but I can't think of any other way to accomplish this.
Creating a RR from a relative date range ("Last 30 Days", "Yesterday", "Last Week", etc) does just this. The specific start and end dates from the URL's query string are ignored if the URL also contains a relative date range. In fact, you can omit entirely (and it would probably be much easier to read if you did) the parameters for start date and time as well as end date and time from your RR URL.
http://1.2.3.4/NmConsole/Reports/Full/Device/Performance/RptCpuUtilization/RptCpuUtilization.asp?_nDeviceID=1&_nReportID=195&RptCpuUtilization.nStatisticalCpuIdentificationID=1&_oComboDateRange=Last%2030%20Days
http://1.2.3.4/NmConsole/Reports/Full/Group/Performance/RptGroupCpuUtilization/RptGroupCpuUtilization.asp?_nDeviceGroupID=0&_nReportID=160&_oComboDateRange=Last%207%20Days
Would this work?
Create a maintenance schedule that lasts for the entire day except the small window where you want the monitor/device to poll.