So if I understand correctly, you would like to resize the course depending on the screen resolution?
I have tackled a similar problem, however, I did not find a clean fix. I had a lot of widgets that I wanted to increase or decrease in screen space as you scroll in and out. My fix is a little hack, but it works. On scroll, I would update the size of the widget, all driven from a curve. In theory, you could query the screen resolution and use a similar curve to set the size of the cursor.