Set GUI within 4 points - Matrix Rotation/Distortion

Hi, I have four corner gameobjects(top left(x1,y1), top right(x2,y1), bottom left(x1,y2), bottom right(x2,y2)). Now I would like to display the GUI within these 4 points. I already got the position and scale part, but i have really now idea how to start with the rotation/distortion part. Is that even possible? And how?

My code till now:

 // Calc correct GUI Matrix within 4 points
 public GameObject tl;
 public GameObject tr;
 public GameObject bl;
 public GameObject br;
 public Camera camera;
 private Matrix4x4 CalcMatrix()
 {
     // Get ScreenPosition of the points
     Vector3 tlsp = camera.WorldToScreenPoint(tl.transform.position);
     tlsp.y = Screen.height - tlsp.y;
     Vector3 brsp = camera.WorldToScreenPoint(br.transform.position);
     brsp.y = Screen.height - brsp.y;
     Vector3 trsp = camera.WorldToScreenPoint(tl.transform.position);
     trsp.y = Screen.height - trsp.y;
     Vector3 blsp = camera.WorldToScreenPoint(br.transform.position);
     blsp.y = Screen.height - blsp.y;
 
     // Calculate Values
     Vector3 Pos = new Vector3(tlsp.x, tlsp.y, 1.0f);
     Vector3 Scale = new Vector3(((brsp.x - tlsp.x) / Screen.width) * Screen.width / 800,
         ((brsp.y - tlsp.y) / Screen.height)*Screen.height/600,
         1.0f);
 
     return Matrix4x4.TRS(Pos, Quaternion.Euler(new Vector3(0, 0, 0)), Scale);
 }