This is actually a showstopper. Most of the meetings have to be planned in advance. People connect from different places (typically they leave their desk and go to meeting room from which they can start the conference call meeting). They do not necessarily have direct access to their emails right before the meeting.
In the Netviewer one2meet original version, you can receive the session ID beforehand. So I do not understand why this functionality does not exist in the ProjectPlace version.