You can't "hit the ding." The nature of the system is that the meter is laid down several pixels at a time, probably ranging from 8 to 32. Therefore there is no "point,", merely a range.
Further, WGT does not know when the mouse was clicked. The click is detected by the system, then placed into a queue for the program that the system presumes that the click was intended for.
The program in question services all the events that are in its queue. These can be mouse events, keyboard events, timer, and a plethora of others. There is certainly no guarantee of how soon the ding click will be processed.
The playability of the game is based upon probably getting a click event when one is within a certain number of pixels before or after the "ding point."
I'm betting that you have seen this, yourself. You click a little early or a little late, you still get a ding. You click what you think is pretty close, and you don't get a ding.
Just do the best you can.
My personal technique is to drag toward the upper left until I get the strength that I want. I then release and let it go. I don't move my mouse after the release. I just watch the meter and click (wherever the mouse is) when I think the time is right.
I ding 50% to 75% of the time, depending upon whether I'm having a good day or a bad day.
A ding is better than a missed ding, but not by much if the missed ding is close.
My personal preference is to adjust shots by moving the triangle. I never intentionally miss the ding except on shot shaping.
All this stuff is personal preference and predicated on what you think you can do or not do.