Move RB through any place on gate [not center]

Hi,

I have a space ship with a RigidBody and I have a gate in the distance. I want the RB to go through the gate. Currently I am using this to calculate the turn ratio:

Code (CSharp):

1. void Update () {
2.     angleToNextGate = GetAngleToNextGate();
3.  
4.         /* angleToNextGate
5.             * ===============
6.             * Next Gate is left = Positive angle -> dirPicker = -1f
7.             * Next Gate is Right = Negative angle -> dirPicker = 1f
8.             * */
9.            
10.         //  FlightController axis values go from 0f to 1f
11.         AccelerateDependingOnAngle();
12.         Steering();
13. }
14.  
15. #region Path calculations
16. float GetAngleToNextGate()
17. {
18.     Vector3 dir = Vector3.zero;
19.     float angle = 0f;
20.  
21.     if (Nav.nextGate != null)
22.     {
23.         dir = Nav.nextGate.transform.position - transform.position;
24.         angle = Vector3.Angle(dir, transform.forward);
25.         dir = Vector3.Cross(dir, transform.forward);
26.  
27.         if (dir.y < 0)
28.         {
29.             angle = -angle;
30.         }
31.     }
32.  
33.     return angle;
34. }
35. #endregion
36.  
37. #region Controls
38. void AccelerateDependingOnAngle()
39. {
40.     if (Mathf.Abs(angleToNextGate) < 60f)
41.     {
42.         FC.axisValueAccelerate = 1f;
43.     }
44.     else
45.     {
46.         FC.axisValueAccelerate = 0f;
47.     }
48. }
49.  
50. void Steering()
51. {
52.     if (angleToNextGate < 0f)
53.     {
54.         dirPicker = 1f;
55.     }
56.     else
57.     {
58.         dirPicker = -1f;
59.     }
60.  
61.     if (Mathf.Abs(angleToNextGate) > 40f)
62.     {
63.         FC.axisValueSteer = dirPicker;
64.     }
65.     else
66.     {
67.         FC.axisValueSteer = dirPicker * Mathf.Abs(angleToNextGate) / 40f;
68.     }
69. }

This works very good when the RB is far away from the gate. However, the gate is wide and if the ship approaches from the left for example, I want the ship to go through the left part of the gate and not flying to the center of the gate first.
Kinda like optimizing a race line, to go through the spot in the gate that is the shortest way instead of going through the center of the gate.

I was thinking in approaching to the center first when the ship is far and when it reached a certain distance, not focusing on the center any more but the shortest path. Any ideas how to calculate that?
Side note: Not all gates have the same width.