I'm sorry, yes, it's solved, well, closed, at least. My references were set, but I never could determine what was causing the error message.

My solution was giving up on the IE idea and just manipulating the HTML file through Word. I knew from the start of this post that was an option; it would have been a bonus to make the IE process work, but it wasn't necessary to my procedure, so I'm skipping it.

Thanks anyway for everyone's great suggestions!