Is it possible to publish Captivate HTML5 file to EPUB?

Hi

I am wondering if it is possible to publish Captivate files to epub. I see that there  are now direct way of doing this, but as epub is packed HTML5, I wondered if it could be done by publishing HTML and convert it to epub. However the structure of the published HTML5 from Captivate is different from other unpacked epub files I have seen.  Is it possible at all? Has anybody tried and succeeded or failed and can tell me if it is possible at all?

Thanks

Jan