Plugin To Extend Editor By DLL which contains Mono behaviours

I am developing a plugin which extends unity3d editor. this plugin will append as a managed dll to the project in editor folder. structure of plugin is something like this:

 'Editor Folder'
 '-- CustomPlugin.dll'
 '    |-- CustomeEditor.cs -- main editor class which inherits EditorWindow'
 '    -- AnchorNode.cs --a MonoBehaviour'

There is a class something like this :

 [ExecuteInEditMode]
 
 public class AnchorNode :MonoBehaviour
 {
     public GameObject next=null;
     public GameObject prev=null;
 }

The plugin class which extends EditorWindow class use MonoBehaviour below like this:

 var nextAnchor = currentAnchor.GetComponent<AnchorNode>().next;

So everything go ok unitl I want to attach AnchorNode script in dll to game objects in game . I can't and unity says : this is an editor script. Please note I have placed dll in Project's Editor folder because it is a plugin for editor and dll has AnchorNode class which inherits from MonoBehaviour and this MonoBehaviour should be attached to game objects within scene.

I have tested this method but I can't get "next" attribute, because Component class has no attribute named "next" :

 var anchorNode =currentAnchor.GetComponent("AnchorNode");

So How Can I use MonoBehaviour in a dll which is placed in editor folder?

Thanks in advance...