This script converts a georeferenced IOF XMLv3 file to a KML file. By default, all courses are included, each in a separate folder in the KML file. For use as a MapRun course, you need to delete all but the required course for any maprun event. This can be done in Google Earth, or by using a text editor on the KML file.
Alternatively, if you know which number course you want, you can select just that course for conversion from the file. If necessary you can determine the require course number by looking at a conversion of all the courses in either Google Earth, or by using my KML Course Placemarks Lister script.