function saveRemoteFile(From, To)
{
  var oXmlHttp = new ActiveXObject("Msxml2.XmlHttp.4.0");  //Change to version 3 if necessary
  oXmlHttp.open("GET", From, false);
  oXmlHttp.send();
  if (oXmlHttp.status == 200)
  {
    var oStream = new ActiveXObject("Adodb.Stream");
    oStream.type = 1; //Binary
    oStream.open();
    oStream.write(oXmlHttp.responseBody);
    oStream.saveToFile(To, 1 && 2); //Create if needed and overwrite if necessary
    oStream.close();
  }
  else
  {
    throw new Error(oXmlHttp.statusText);  //Needs improving
  }
}

saveRemoteFile("http://myserver/myfolder/myfile.xls", "C:\\myfile.xls");

var oExcel = new ActiveXObject("Excel.Application");
var oWB = oExcel.workbooks.open("C:\\myfile.xls");
//oExcel.visible = true;
var oWS = oWB.worksheets(1);
document.getElementById("divOutput").innerText = oWS.Range("A1").value;
oExcel.quit();