Okay, I understand. In that case you'll just need to use a global variable. Let's call it picked_angle.

Code:

---

var picked_angle;

starter choose_way()
{
   randomize();
   picked_angle = random(160) + 10;
}

action X
{
   while(picked_angle == 0) { wait(1); } // wait until choose_way has run
   my.pan = picked_angle;
   while(1)
   {
      temp.x = 5*time_step; // change 5 to whatever speed you want
      temp.y = 0;
      temp.z = 0;
      c_move(me,temp,nullvector,null);
      wait(1);
   }
}

---

Now, all entities with action X attached will travel in the same (but random) direction.

Better?

EDIT: changed choose_way to a starter, and added WHILE at the beginning of X