[Orgmode] icalender export: limited number of repeated events

[knubee]

I need to share some of my calendar data with co-workers. One of
the biggest limitations I encounter with emacs/icalender is that
it does not seem to support a limited number of repeated events.

As far as I can tell, the way to specify this is with regular
expressions. Example:

* TODO Something every Sunday, 10:00-12:00, for 2 months
  SCHEDULED: <%%(and (= (calendar-day-of-week date) 7) 
                        (diary-block 1 6 200 31 7 2008)) 10:00-12:00>

I have not been able to figure out how to export these to an .ics
file.

Google calendar, on the other hand, will export something like
the following:

BEGIN:VEVENT
DTSTART:20080601T100000
DTEND:20080601T120000
RRULE:FREQ=DAILY;UNTIL=20080731

Has anyone else managed to get a limited number of repeating
tasks/events to export correctly to .ics format?

thanks.