why not try?

 

function CuteEditor_OnCommand(editor,command,ui,value) {
  if (command=="Paste") {   
    var oEditor = document.getElementById(editor.id);

    var sHTML = oEditor.getHTML();

 

    //Parse HTML and Clean

    sHTML = sHTML.replace('<br />', '</p><p>');

 

    oEditor.setHTML(sHTML);

  }              
}