Hello,
As you know, you can not import anything rigged into the Lumion, the only animation that can be imported to Lumion is the simple move, rotate and scale animation and beyond that, no animation can be imported(such as vertex animation).
Anyway, we have had the same issue with a project that we did in Lumion and we wanted to add characters playing tennis there, what we did for that project was to do the camera tracking on the Lumion rendered animation and then animate the character in another software and finally composite them together.
We can help with the same approach for your project.
You can read about our clients' feedback and check our portfolio here:
https://www.freelancer.com/u/kingjoon.html
Best regards,
Art Land Design