this is code that i am using for my skybox,, its generally a huge geosphere model that follows player all the time, making a nice sky effect,,,

Code:

---

function follow_player() // Used for Skyglobe
{
while (1)
{
my.x = camera.x;
my.y = camera.y;
//my.z = camera.z +1;     //If you have a space flight level or something, you can turn this on.
WAIT (1);
}
} 

 

Action Skyglobe
{ 

my.hidden = on;
my.passable = On;
my.nofog = On;
my.unlit = On;
my.ambient = 100;
follow_player();
//---------------------- 
sun_light = 10; // Amount of Light
sun_angle.pan = 360; // Compass Direction the Light will come from
sun_angle.tilt = 30; // Sunlights Hight 
//---------------------------
} 

---

just apply it to your horizon model