[Quickie]

use trigonometry

pawn Код:

new Float:Ox,Float:Oy,Float:Oz,//objects coords
      Float:Px,Float:Py,Float:Pz,Float:Pangle;

GetPlayerPos(playerid,Px,Py,Pz);

new Float:Hypotenuse=GetPlayerDistanceFromPoint(playerid,Ox,Oy,Oz);
new Float:Adjacent=floatadd(floatabs(Ox),(float(Px)*(-1)));

Pangle=acos(Adjacent/Hypotenuse)*(-1);

SetPlayerFacingAngle(playerid,Pangle);
SetPlayerControllable(playerid,1);

i didnt test the code but somehow atleast should give u an idea