Click and drag an object together with a separate object

Hey,

I want to move an object around in my 2D project using my mouse input, which works fine so far, but at the same time a different object should move as well. It should work as if the second object was a child of the first one, so that is moved in the same way, but not right below the mouse. While this is easily done when they are parent and child, my objects are not.

From the object I am dragging, I do have a reference to the second object, but how do I move it along? The only method I could think of right now would be some arithmetic on transform.position with explicit numbers but I cannot imagine there is no other way than that.

I don't know if this is relevant but here is my code for moving so far:

 void OnMouseDown() {
 
         pressed = true;
 
         if (!isClone) {
             if (transform.parent.name.Contains("AND")) {
                 clone = Instantiate(Resources.Load("FB/FunctionBlock_AND")) as GameObject;
                   ...
             }
         }
         screenPoint = Camera.main.WorldToScreenPoint (gameObject.transform.position);
 
         offset = gameObject.transform.position - Camera.main.ScreenToWorldPoint (new Vector3 (Input.mousePosition.x, Input.mousePosition.y, screenPoint.z));
     }

and

 void OnMouseDrag() {
         Vector3 curScreenPoint = new Vector3 (Input.mousePosition.x, Input.mousePosition.y, screenPoint.z);            // Current touch point
 
         Vector3 curPosition = Camera.main.ScreenToWorldPoint (curScreenPoint) + offset;                                // Current touch point converted to point in scene
         if (!isClone) {
             clone.transform.position = curPosition;                                                                            // Move clone to this position
         } else {
 //            transform.position = curPosition;        // non clamped version
             // Mathf.Clamp() restricts the movement of the dragged FB to the working area
             transform.parent.position = new Vector3 (
                 Mathf.Clamp (curPosition.x,
                     (breadboardLeft.position.x+breadboardLeft.GetComponent<BoxCollider2D>().bounds.size.x)+0.4f, 
                     breadboardRight.position.x-breadboardRight.GetComponent<BoxCollider2D>().bounds.size.x),
                 curPosition.y,
                 curPosition.z);
         }
     }