Yahoo Calendar is able to import from a localendar iCalendar feed, however Yahoo Calendar currently does not export to an iCalendar URL (like Google Calendar, for example)
Yahoo Calendar can export to a static iCalendar file. However, localendar currently cannot load a static iCalendar file.
If Yahoo Calendar adds support for a public iCalendar URL, then you should be able to import it into localendar by following the Importing iCalendar into your localendar directions.