Curves resolution

Is it possible to implement a X,Y position value for a point on a curve. I've found myself doing curve tweaks where i'm limited by the mouse resolution/size of the curve graph which means i either over/under correct. (LAB colourspace is a nightmare)

If you could make a box with a numerical value that represented the point you click on the graph, it would A - make sure your values are even/exact rather than eyeballing the grid and B, allow for minute tweaks beyond the limits of the window/screen res.