I don't understand the question -- it appears that the "winch" from which the rope hangs being 30m from the ground is immaterial to the question. All that matters is the length of the rope (i.e. the amount of displacement or work that must be done against the gravitational field). I assume that you are not expected to account for 1/r^2 deviations haha.
Clarify before I work out the problem please.