Access ICal UID from VSTO

Hello,

I'm working on a system that will syncronize appointments between outlook and my web application through web service.

My application already export appoints to outlook with ics files (ical)

BEGIN:VCALENDAR
VERSION:2.0
METHOD:PUBLISH
BEGIN:VEVENT
DTSTART:20060529T184000Z
DTEND:20060529T184500Z
LOCATION:room1
UID:12345
TRANSP:OPAQUE
SEQUENCE:0
DTSTAMP:20060529T210534Z
DESCRIPTION:Test this is a test
SUMMARY:Test
PRIORITY:5
X-MICROSOFT-CDO-IMPORTANCE:1
CLASS:PUBLIC
END:VEVENT
END:VCALENDAR

this works great, but my problem is with the UID. I can open the appointment in outlook and do save as "ics" file and I see that outlook has kept the given UID somewhere because my UID value 12345 will still be there.

Now I build an Outlook plugin with VSTO and I'm calling my webservice to update the outlook appointment and I want to use the UID has my key. However, I can't find how to access the UID property inside my VSTO project.

I search alot on google and from what I found how the uid property is store in MAPI item properties and since it not easy to try the microsoft CDO 1.21 example in this KB entry http://support.microsoft.com/ id=899919

but the result i get
(040000008200E00074C5B7101A82E0080000000000000000000000000000000000000000110000007643616C2D556964010000003132333400)
looks like another internal guid instead of my orginal UID (12345)

Can anyone show me how to get my uid value

thanks!

Mark