This is an interesting situation. It may be that the most expedient thing would be to have the authors email the director/track director the final abstracts and/or papers, who can then upload them for presentation and archiving. This issue has been discussed previously here for inclusion in the next OCS release: viewtopic.php?f=3&t=2675
If you have any comments you'd like to add, please feel free to do so either in that thread, or here. If I'm missing something, please let me know.