What you could do is use an Animation Pattern (I'd use Timeline for this but that's just me!) and assign the Time storable to a UISlider. That fairly simple to setup and you'll get a nice and easy result.
If you use Timeline to do it:
1. Add Timeline to your Person atom
2. Targets tab: Add the "control" target
3. Edit tab: Toggle "loop" off
4. Rotate the model to the left, move the scrubber to 1s, rotate it to look forward, move the scrubber to 2s, rotate it to look to the right. Now when you move the slider left and right, you'll see your model rotate.
5. Add a UISlider atom
6. In the Triggers, add the Person atom, Timeline storable, Time param. Now the slider should animate the person!
What I personally like with using Timeline, is that it's then easy to do things like animate the upper body and head along with the body rotation, lights, etc. in sync. But, animations patterns work perfectly fine and I'm sure there's a plugin somewhere that does exactly that, but I thought I'd share my approach