I've looked into this before and I don't believe IBO currently supports this part of the API.  In my case I needed the ability to restore a database from the client side - i.e. the user selects a local backup file and the database on the server is restored from it.  Possible via the API but not via IBO.  However I did manage to add support by making alterations to IBOServices.pas, so I'm sure the same could be done for remote backups.  I'd be happy to share my code if it might help.