plot (something) on (something)
To trace or draw a route or path on top of or along something. We plotted a way home on a scrap of paper we found in my bag. Using the stars as a compass, we were able to plot a course on the map we'd brought with us.
plot something on something
to draw a route or outline on something. He plotted the course they would be taking on a map of the area. The captain plotted the course on a chart of the upper reaches of the Nile.