First:
#include <math.h>
#define PI 3.14159265 

Then:
On_Beacon_Creation {
   float facing = Commands->Get_Facing(planter)
   Vector3 pos = Commands-> Get_Position(planter)
   pos.X += -1*(cos(facing*(PI / 180)))
   pos.Y += -1*(sin(facing*(PI / 180)))
   // -1 is the distance away from the player can be set to more/less
   Commands->Set_Position(beacon,pos)
}