I had done a similar thing in UDK about a year ago. But unfortunately I dont have the code with me. But I think I can give a basic idea of how I did it.
So in my UDK project which was a side scroller, the player controlled a ship with left and right sticks. The left stick controlled the ships height (UP-DOWN) and moved it to the right or left. The right stick controlled whcih direction the ship was facing and thus where the ship would fire bullets.
I have a float called facingDirection, which is 1 when ship is facing towards right hand side and -1 when facing towards the left hand side. Then I switched between 1 and -1 based on the right analog stick horizontal axis value. Multiply this value with the normalized vector that points to the right hand direction (got from the camera). Convert this to a Rotator and set as the Rotation of the Actor.
PS: I will see if I can find the original code and post it here if I find it.
You must also check FaceRotation() function in APawn