OK so I found this video where a guy makes his own variocam tool, but buying everything doesn't seem to be worth it. However, he did tell us the size and pitch of the thread: M5 x 0.8
It's worth lookng at the video.
https://www.youtube.com/watch?v=ygSKeRW5F2U
Then I found a source for LEFT HAND M5-0.8 allthread, but longest they have 10CM. Is that long enough? I don't know. $13.04 Each.
https://accu-components.com/us/left-hand-thread-threaded-bars/409371-HTBL-M5-1000-A4?google_shopping=1&c=2&gad_source=1&gbraid=0AAAAADI7_w57vz2S-a5EuY8ShHnKa0XBa&gclid=CjwKCAjwn6LABhBSEiwAsNJrjqzn0v3UBW_rck_eByir Phj6HkeKNTvzkQTYQLJGmKplfkA7lzsy6xoCM6AQAvD_BwE
Lastly, you'll need left-hand M5 nuts, the same place as above sells them: (Doesn't spec pitch size, so you may want to contact them and ask.) $1.41 Each.
https://accu-components.com/us/left-hand-thread-hex-nuts/73115-HPNL-M5-A2