Usually you don't read directly the WindowsEventLogs, and use the special inputs that calls the windows system API.
However if you have evt files exported (not locked or touched by windows), you can to monitor them as regular files :
please apply the correct sourcetype based on the actual log type ( by example WinEventLog:Application)
see http://splunk-base.splunk.com/answers/37343/sourcetype-for-windows-event-logs
please import the log file on the same OS version in order to translate them correctly
see http://docs.splunk.com/Documentation/Splunk/5.0/Data/MonitorWindowsdata#Index_exported_event_log_.28.evt_or_.evtx.29_files
... View more