I am not exactly sure what you mean, but maybe try vec_dist...

Code:

---

action enemy {
   my.push=1;
   my.polygon=on;
		while(ready_to_play == 1)
	{
		if (vec_dist(my.x, player.x) <= 330) { 
		c_move(me,nullvector,vector(-2,0,0), glide);
		}
		wait(1);
	}
}

---

Not tested, though.

Thanks,
Adoado