well, if all you want is to make a model 'face' the player, than it's just a matter of getting the direction vector from the model to the player, and then converting that to yaw, and feeding the yaw directly into the y component of the angles vector:
pl = player entity
local vector vec;
local float yaw;
vec = pl.origin - self.origin;
yaw = vectoyaw(vec);
self.angles_y = yaw;
do this every frame and it will behave just like a vp_parallel sprite.