Here are the client side APIs:

function getHTML()
   {
    // get the cute editor instance
    var editor1 = document.getElementById('CE_Editor1_ID');
    
    // Get the editor HTML
    document.getElementById("myTextArea").value = editor1.getHTML();
   }  
   
   function setHTML()
   {
    // get the cute editor instance
    var editor1 = document.getElementById('CE_Editor1_ID');
    
    // Set the editor
    editor1.setHTML(document.getElementById("myTextArea").value);
   }
   
   
   function PasteHTML(html)
   {
    // get the cute editor instance
    var editor1 = document.getElementById('CE_Editor1_ID');
    
    editor1.PasteHTML(html);
   }
   
   function SetActiveTab(tab)
   {
    // get the cute editor instance
    var editor1 = document.getElementById('CE_Editor1_ID');
    
    editor1.SetActiveTab(tab);
   }
   
   
   function setFocus()
   {
    // get the cute editor instance
    var editor1 = document.getElementById('CE_Editor1_ID');
    
    editor1.FocusDocument();
   }
   
   
   function ExecCommand()
   {
    // get the cute editor instance
    var editor1 = document.getElementById('CE_Editor1_ID');
    
    var CommandObj = document.getElementById('Commands');
    var cmd = CommandObj.options[CommandObj.selectedIndex].text;
    var val = CommandObj.options[CommandObj.selectedIndex].value;
    editor1.ExecCommand(cmd,false,val);
   }
   
   function CE_attachEvent()
   {
    // get the cute editor instance
    var editor1 = document.getElementById('CE_Editor1_ID');
    
    //Get the editor content 
    var editdoc=editor1.GetDocument();

    // attach Event
    editdoc.attachEvent('onkeypress',HandleChange);
   } 
   
   
   function HandleChange()
   {
    // get the cute editor instance
    var editor1 = document.getElementById('CE_Editor1_ID');
    //Get the editor content 
    var editdoc=editor1.GetDocument();
    alert(editdoc.body.innerHTML);
   }  
    
   
   function CE_detachEvent()
   {
    // get the cute editor instance
    var editor1 = document.getElementById('CE_Editor1_ID');
    
    //Get the editor content 
    var editdoc=editor1.GetDocument();

    // detach Event
    editdoc.detachEvent('onkeypress',HandleChange);
   }

To answer your question, you can just use the editor1.PasteHTML(html) method.