Hello again, Dan.
I apologize for not having been as inclusive as I should have been, with the information, but the tool that I was referencing is the SketchUp Team’s ‘Bezier Curve Tool’.
I really need to have such a tool, but need one which would feature a more accurate manner of the committment action. Right now, whenever I click to set my curve, I find that I have to click a second time - which always results in my line jumping away from where I had it set. Of course, it could be that there is something that “I” am doing wrong, and I am attempting to explore that possibility right now.
I will also look into the Fredo Bezeir Spline tool extension, to see if the same issue occurs.
I thank you for stepping in to help see me through this.