I believe he actually meant how to change rotation during time interval. ****, use Lerp (Rotator) to achieve that.
I have another question about bone rotation, how to define angles which bone is allowed to rotate? LookAt in UDK had something like that, as documentation [says][1]. Currently rotating it as shown on image below.
Had to set pitch value to 90 to block pitch rotation and make head positioned “right”, is there a better way to achieve it?