Captivate 9: captions on slide with video

hello

I have a captivate file comprised of several slides, each containing a video. How do i add closed captioning to these slides?

The videos were created in Camtasia Studio 8 and include captioning, but the captioning does not transfer over to Captivate (as Captivate can only import a .mp4 file and the captioning in the Camtasia file is included in another file that the .mp4 points to).

I don't see a 'closed captioning' option on the slides that contain a video. I must include closed captioning in my project as this is a requirement.

If anyone can help me address this question, I would very much appreciate it.

Marion