Thanks very much for sharing the XSLT, it worked for us straight out of the box
For those who are unclear on how to use it.
1. Add a post build action "Create xUnit test result report" and Add a "Custom Tool"
2. In the pattern text box point jenkins to the ranorex result xml (file ending with ".rxlog.data")
3. In the custom stylesheet text box give the relative url for the xslt that you have just downloaded and saved