<html>
<head>
<script></script>
<!-- a -->
<script>
window.onload=function(){
  let s=window.getSelection();
  let r=document.createRange();
  r.selectNode(document.getElementById('b'));
  s.addRange(r);
  try{window.getSelection().modify('extend','forward','word')}catch(e){}
  let o=document.getElementById('a');
  o.parentNode.replaceChild(document.createElement('col'), o);
}
</script>
>
<template id='a' contenteditable='true'></template>
<header id='b'></header>
<!-- a -->
</html>