You can do this, but by adding HTML code after generating template code.
You can simply find in generated template code your text you add in description, and after this text add code generated on this page:
http://www.isdntek.com/tagbot/YouTubeConverter.htm
(we not respond for this page, so we do not know this page will work all time because we do not update this)
After this you paste all code to ebay, and you should have video in template.
If you need help with this, find freelancer HTML developer to tell you exactly how to do this or do this for.
