How ironic! The registration confirmation message for the GroupWise for New Employees class doesn't have a machine-readable calendar invitation attached.
It does have an HTML description of the event that's clearly machine-generated:
Oh for hCalendar!
That is: if the registration system added just a little hCalendar markup, and if GroupWise grokk'd hCalendar, then we'd be all set. Or if the registration system added hCalendar markup and used it to generate a .ics version.
Hmm... does GroupWise actually support .ics attachments from other systems? Or is it just because I'm using Evolution as my GroupWise client that I think this would work?