Corners of Wheelie
It is possible to navigate corners while doing a wheelie and requires much the same inputs as cornering on two wheels. When approaching the turn it is best to look through the turn towards the exit as a bike goes where the rider looks.
Turning the bars in the direction the rider wants to go is the initial stage and only requires minimal movement, couple this with slightly shifting upper body weight (mainly head and shoulders) again in the direction of the turn and the bike should start to lean over and turn. This is not an easy maneuver because the bike now is very biased as to which side it wants to fall over on to. Concentration is needed to keeping the wheel off the ground and countering the sideways balance. Turning the bars outwards and shifting body weight to the outside will help keep the bike on a smooth path around the turn.