Well for a good equation to position things relative to a referenced object use this http://geck.gamesas.com/index.php/Useful_Scripts
and scroll down to forced relative orientation. It's how I got nightkin to randomly stealth and jump around behind the player a la displacer beasts.
Scripting maths isnt one of my strong points, but these are the two sets of equations ive been using to test this with:
(set upon entering menu mode)
set CamAngle1Z to player.getangle Z +235
;Rotates Camera Angle 1 to point behind the player 235 degreesset CamPos1X to player.getpos x + (sin CamAngle1Z) * 50
;Pulls Camera Pos 1 out in X 50 units based on Z angleset CamPos1Y to player.getpos y + (cos CamAngle1Z) * 50
;Pulls Camera Pos 1 out in Y 50 units based on Z angleset CamAngle1Z to CamAngle1Z +150
;Rotates Camera Angle 1 back to 0 and adds 25 degrees in order to point towards the Targetset CamAngle2Z to convoTarget.getangle Z +125
;Rotates Camera Angle 2 to point behind the target 125 degreesset CamPos2X to convoTarget.getpos x + (sin CamAngle2Z) * 50
;Pulls Camera Pos 2 out in X 50 units based on Z angleset CamPos2Y to convoTarget.getpos y + (cos CamAngle2Z) * 50
;Pulls Camera Pos 2 out in Y 50 units based on Z angleset CamAngle2Z to CamAngle2Z +210
;Rotates Camera Angle 2 back to 0 and adds 25 degrees in order to point towards the PlayerUsing these to offset the Player during IsTalking should place him/her roughly up by the face of the Clone & Target.
Pulling out another 10 or 20 units and playing with Z pos based on NPC height may help to bring in more of the shoulder.
Youd also need to set the camera up to take into consideration whether they're sitting.
If however the NPC is restrained too early and they aren't allowed to initially turn to face the player then these may not work as intended.
Edit:
Also Ive just found out that adding a simple wander package with only the Must Complete and Must Reach boxes ticked,
turns off head tracking during dialogue and still allows you to set a target with the look command.