Graph- please let me add Vertical and horizontal lines with highlighted data label and axis values

I need to

1. Add vertical and horizontal lines from several data points on multiple data series on a single graph.

2. Show axis labels(values) where those vertical and straightlines cut the axes.

3. Showing data label (value) only on few specific data point (not all data point but show on desired data point).

4. highlight the horizontal and vertical lines.

I have already tried:
a. screenshot and photoediting. makes the graph irreproducible, non-processable and non-searcheable. So it does NOT help

b. Using geometric figures and/or lines: Horrible outcome; added lines slightly changes its position on the graph with nearly every attempt on chart resize, file saving, file opening to some other computer, file conversion etc. NOT serves the purpose. Also data point hard to locate.

c. The average feature and the error bar: got this solution from youtube but its complicated, difficult and very time consuming.

d. The conditional statement. got this hack from youtube but too difficult and i could not implement it.

e. Gridlines: I could not highlight individual gridline. A set of gridlines (such as minor vertical, etc.) TOGETHER changing atributes. Does NOT serve my purpose.

Regards.
Thanks in advanced.