How to develop Clickable points within a chart which pop up a dialog box for user entry

Question

I have a set of large number of X & Y coordinates in a dataset to generate a graph or a chart. Let us say that I generate a chart using this dataset. I do not have the code for the chart yet, because I do not yet know how to do what I am about to ask help for. Next, I want each of the original coordinates in the dataset, to be clickable individually, on the windows screen showing the chart. For example.. If i click a point on the chart with coordinates (x1, y1), I want a new windows screen or dialog box to open up, where I can enter some additional attributes about the x1, y1 point I just clicked, and it gets saved. Are there C# .NET libraries out there which can help me do that ? Can you please point me to some documentation or examples ? I know how to do windows programming, for UIs, event based methods, submit buttons and all that. That is not the problem. If I create a .png or a .jpg chart, it will be a static picture. I cant click inside it. So i cannot go that route.

Also, I do not have to have a chart.. anything equivalent will work too. Basically, I want to be able to generate a grid from a dataset of x, y coordinates, and then be able to click individual coordinates points on the grid, bring up a dialog box, and save the info i enter into the the dialog box for that point on the grid.

Thanks D