customTask to duplicate hits for a specific domain

customTask_duplicateHits.js

function() {
  //Credit to Simo Ahava
  //https://www.simoahava.com
  var url = {{Page URL}}
  if(url == "specific domain you are interested in")
  {
    // Replace newTrackingId value with the UA property to which you want to duplicate hits
    var newTrackingId = 'UA-XXXXX-Y';  
    var globalSendTaskName = '_' + newTrackingId + '_originalSendTask';
    return function(customModel) {
      window[globalSendTaskName] = window[globalSendTaskName] || customModel.get('sendHitTask');
      customModel.set('sendHitTask', function(sendModel) {
        var hitPayload = sendModel.get('hitPayload');
        var trackingId = new RegExp(sendModel.get('trackingId'), 'gi');
        window[globalSendTaskName](sendModel);
        sendModel.set('hitPayload', hitPayload.replace(trackingId, newTrackingId), true);
        window[globalSendTaskName](sendModel);
      });
    };
  }
}