How to generate a pre-filled form URL for Google Form

I required something similar for users to go and edit their response, take a look here: http://productforums.google.com/forum/#!topic/docs/LSKKCR3VHC8

Copy / paste code below:

function assignEditUrls() {
var form = FormApp.openById('1MonO-uooYhARHsr0xxxxxxxxxxxxxxxxxxxxx');
//enter form ID here

  var sheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName('Form Responses');

    //Change the sheet name as appropriate
  var data = sheet.getDataRange().getValues();
  var urlCol = 4; // column number where URL's should be populated; A = 1, B = 2 etc
  var responses = form.getResponses();
  var timestamps = [], urls = [], resultUrls = [];

  for (var i = 0; i < responses.length; i++) {
    timestamps.push(responses[i].getTimestamp().setMilliseconds(0));
    urls.push(responses[i].getEditResponseUrl());
  }
  for (var j = 1; j < data.length; j++) {

    resultUrls.push([data[j][0]?urls[timestamps.indexOf(data[j][0].setMilliseconds(0))]:'']);
  }
  sheet.getRange(2, urlCol, resultUrls.length).setValues(resultUrls);  
}

This is not possible right now but this request is being tracked on the Issue Tracker here. Please add your use cases there and watch it for updates.