Thanks for the interesting link but it doesn't solve my problem.

>>Hi all!
>>
>>I'm creating an Outlook meeting request within my C# code and the user can send it to the attendees.
>>One special attendee uses two calendars - one private and a public one, the latter is the default one.
>>
>>Can this user (and everybody else) choose which calendar should be used to save this meeting request?
>>
>
>Not an answer, but may be helpful
>
>Link on MS site