ANGLE temp_ang;
VECTOR temp_vec;
vec_set(temp_vec, entity_you_want_check.x);
vec_sub(temp_vec, player.x);
vec_to_angle(temp_ang, temp_vec);
if((player.pan > temp_ang.pan - 5)&&(player.pan < temp_ang.pan + 5)) //play with 5
{ //your code }

VECTOR temp;
vec_set(temp, vector(player.x,player.y,player+200); //above the player's head
c_scan(temp, nullvector, vector(360,0,100), /*you have to look for the modes yourself*/);
if(you != NULL)
{
your code
}