I didn't have a adequate answer off the top of my head, so I passed this up. Let me see what I can do.

Currently you cannot really move the camera while locked on, you can turn it, but you have to manually hold it there. It'll snap back to right behind you as I'm sure you know.

If you don't like it, what I did was turn off auto-lock in Main Menu -> Configuration and then manually hit 'C' whenever I actually want to lock on. You can still attack as long as there's the 3-arrow indicator on your target, as your character will turn toward the target to perform the action, but you can move the camera around however you want.