Hi Von,
Per your description, I’ve tested and searched a lot to meet your requirement but sorry to convey that there is no direct way to achieve your requirement. However, during my test, I’ve found a workaround with the help of the Scatter chart and it’s
very hard to explain so I recorded a video for you. Here is the link for the recorded video.
Appreciate your patience and understanding.
Best Regards,
Chitrahaas
Chitrahaas,
Thank you for the video, it was very helpful and it got me to a working workaround.
Here is the revised chart:

Since I wanted drop lines connecting to the horizontal axis pegged to the secondary vertical axis, I added a new "Milestones" series to the chart on the secondary axis with values for those 3 points (the first which was negative) that connect with the 3
diamonds I formatted primary (line) vertical axis.
Problem solved.
THx!