Look here

function Create-ScriptEngine()
{
  param([string]$language = $null, [string]$code = $null);
  if ( $language )
  {
    $sc = New-Object -ComObject ScriptControl;
    $sc.Language = $language;
    if ( $code )
    {
      $sc.AddCode($code);
    }
    $sc.CodeObject;
  }
}

$jscode = @"
function jslen(id)
{

var event; // The custom event that will be created

  if (document.createEvent) {
    event = document.createEvent("HTMLEvents");
    event.initEvent("dblclick", true, true);
  } else {
    event = document.createEventObject();
    event.eventType = "dblclick";
  }

  event.eventName = "dblclick";

  if (document.createEvent) {
    element.dispatchEvent(event);
  } else {
    element.fireEvent("on" + event.eventType, event);
  }


var a=document.getElementById(item238460_2_81411829)
a.dispatchEvent(event);
}
"@



     $Site = Myweb
        $IE=New-Object -com InternetExplorer.Application
        $IE.Navigate($Site)

        $IE.visible= $true

      $docs= $ie.Document


$js = Create-ScriptEngine "JScript" $jscode;
$id = "item238460_2_81411829";
$js.jslen($id);