This script is highly specialized, I don't recommend downloading and installing it unless you know you need it. Which you probably don't. Seriously.
This script lets you pick 2 vertices. It then takes the YZ coordinates from the first vertex and the X coordinate from the 2nd vertex and use those 2 points to create a new point, and it adds a construction point in that location.
Plugins > Chris Fullmer Tools > YZ + X. Select the first point, then the 2nd. It will add a construction point. This plugin does not work right if the model axis has been altered. So reset the model axis first - sorry!