My suggestion is to clean a bit the xml document, to be something like -
<Exception timestamp="05/05/2014 14:25:53" ...>
<StackTrace>
<Frame exceptionType=...>
<Context>
<Request_ApplicationPath>the_path</Request_ApplicationPath>
<Request_Url_AbsoluteUri>the_url</Request_Url_AbsoluteUri>
<ApplicationName>the_appname</ApplicationName>
</Context>
</Frame>
</StackTrace>
By using the xml sourcetype, you can reach the xml elements via - | spath StackTrace.Frame.Context.Request_ApplicationPath .
... View more