EMBED code is HTML. Captivate content is SWF launched in an HTM wrapper.
If you cannot convert to FLV, have you tried getting it into F4V format instead?
Thanks for the suggestion, Rod! It led me down a path where I finally found my answer. For some reason, the videos I was trying to convert wouldn't do so in the Flash converter that came with Captivate 5.5. I did stumble across the converter for Captivate 5 still on my computer, and using that converted most of the files. The few that still would not convert, I had to get from the video creator in Flash format.
Not a real solid answer, but at least I got what I needed!