OK, so I found a way to do it:
- Rhino: Export the scene as FBX. As per my example, the scene may be a partially assembled Ikea wardrobe.
- Character Creator:
- Import the scene as prop.
- Lock the prop to prevent it from being selected and moved unintentionally.
- Add a character to the scene.
- Pose the character. For my project, I started with motions I found in the Motions for Construction pack. Play back a motion, and stop at the desired pose. Then adjust it as explained in Vad Almafa's video Character Creator- Creating a Custom Pose. (YouTube)
- Export the character in OBJ format. It is in world coordinates.
- Rhino: Import the character. It will be positioned in the exact same place as in Character Creator. No additional steps are necessary, asides from assigning material and textures.
Do this for every character. Unfortunately, it doesn't seem to be possible to pose several characters as part of a group in Character Creator.