[Jalerre]

One simple (but not most precise/accurate) way of going about this would be to have to robot follow the line you draw out using infrared light sensors. While it is following the line, have the robot record data from encoders and a gyroscope. Then have the robot use this data to repeat the path it just followed using just the encoders and gyroscope and without the infrared sensors.

I have never tried this so I don't know how well it would work but it theoretically makes sense.