Hi Jeff!
I will be happy to try to point you in the right direction. Just to clarify what you are looking for here, are you able to import any attendees, or just the orders? Are you also looking to import custom fields for attendees? If so, this will likely be on the tricky side, as these are a feature of Event Tickets Plus, not WooCommerce. So, this will probably take some custom coding to make this happen.
I am not familiar with this particular plugin, but if you can send me a link to it via a Dropbox link (in a private reply), I can take a look and see if there is anything I can recommend!
Thanks,
Jennifer