oh, i get what you were saying... ie. a user "registers" a scheduled conference and then openfire sends the invites on the schedule...
hmm... could be done too... but also would require an OF plugin + a Spark plugin... and some non-standard communication between the 2...
i decided to do a native integration into spark instead of a plugin so that i can avoid doing funny stuff to the actions menu, in order for the "Schedule a conference" button to appear in the same grouping as the other conference buttons, otherwise adding a button to that menu via a plugin will, by default, add it to the bottom of the list... making it feel out of place.