Here are some ideas on how you could achieve motor drive on the right hand sprocket:
Motor direction: Motors that I have seen all turn counterclockwise from the perspective of looking at the drive shaft. There may be clockwise motors that I am not aware of. You can "reverse" the motor turn direction from the perspective of the wheel by turning the motor to have the driveshaft on the left or right side of the rider. The motor is still turning counterclockwise when you look at the drive shaft but it is reversed from the point of view of the bicycle and wheel.
Belt or Chain: When using a chain or belt system, there is no change in direction of turn. Motors typically turn counterclockwise from the perspective of looking at the driveshaft. The direction that the motor turns has to be the same as the direction that the wheel turns. So when you look at the bike from the right side (drivers perspective), and the bike is going forward, the wheel is turning clockwise. When you walk around to the left side of the bike, the wheel turns counterclockwise. So if the motor is a counterclockwise motor, and it uses only belt and/or chain drive, it will have to drive a sprocket on the left side of the wheel.
Gear: Whenever gears meet, direction of turn is reversed. With two gears there is one point where they meet, so direction is reversed. With three gears, there are two points where they meet, so direction is the same as the motor direction. If you have a counterclockwise motor and a gear system with an even number of gears it will have a clockwise output and would connect to the right side of the wheel.
Jackshaft: a jackshaft does not change the direction of turn but it can shift the power take off from one side of the wheel to the other. As long as the gearing system is set up to drive the jackshaft in the same rotation as the wheel, you can choose to drive either side of the wheel.
One way to power the wheel from the right side is to use a motor with a jackshaft, such as the Dax Titan. The jackshaft output sprocket can be moved to either side of the wheel. The Titan also has enough power that you would not need to pedal, which is necessary since you would be removing the pedal drive chain.
This is theory since I have not worked on a Titan yet: You might be able to change the gear ratio to accomodate a typical rear wheel sprocket by changing out the jackshaft input sprocket. The current jackshaft input sprocket is a 10t sprocket and is set up to drive a 44t wheel sprocket. A single speed cruiser style bike typically has about an 18t sprocket (more or less). If you replace the 10t jackshaft input sprocket with a 22t sprocket, you should get enough reduction to allow powering the bike through the right side sprocket that was originally set up for pedaling.
I hope this isn't too confusing.