Passing user selection in Ckeditor

I am working on a project where I need to pass the data selection made before the Ckeditor get loaded.

  /**
   * Get text selection.
   */
  Drupal.xeditor.getSelection = function() {
    var text = "";
    if (window.getSelection) {
      text = window.getSelection().toString();
    }
    else if (document.selection && document.selection.type != "Control") {
      text = document.selection.createRange().text;
    }

    return text;
  };

I created a plugin called 'selection' to get the data from 

Drupal.xeditor.getSelection()

and highlight it inside the Ckeditor. 

/**
 * @file plugin.js
 * Manage selection in Ckeditor.
 */
( function($) {
  CKEDITOR.plugins.add( 'selection', {
    icons: 'selection',
    init: function( editor ) {
      //console.log(XEDITOR.current_selection);
      //console.log(CKEDITOR);
      editor.addCommand( 'selection', {
        exec : function( editor ) {   
          //
        }
      });
      editor.ui.addButton( 'selection', {
        label: 'Content selection',
        command: 'selection',
        icon: this.path + 'icons/selection.png'
      });
      editor.config.contentsCss = this.path + 'css/selection.css';
    },

    afterInit: function (editor) {
      console.log(Drupal.xeditor.getSelection());

      // Auto highlight the string/word selected by the user earlier.

    }

  });
})(jQuery);

However, I have difficulty in achieving what I want. Please see the screenshot below for more details.

Step 1.

On mouseup, I will load the Ckeditor automatically. As you can see in the image below it says that "Loading..."

Step 2.

Step 3.

In step 3 the Ckeditor is fully loaded. In this part I want also the word I selected in Step 1 to be highlighted so user can proceed on formatting and avoid to annoy the user by highlighting again.