A sample java program to convert iCalendar to CSV (for use in Yahoo! Mail, etc). It uses the ical4j library. The library excepts a correctly formatted ics file. In my experience it worked fine with Mozilla Sunbird but Korganizer would cause problems.
This is EXPERIMENTAL software. It's was only a practice application to make use of Java iCalendar libraries and I've never used it in practice, it may not work as expected.