generateAlphaNumeric.js

function generateAlphaNumericLabels(amount) {
  var labels = [];

  for (var i = 0; i <= amount; i++) {
    var appendNumber = 0;
    var offset = 0;

    if (i > 25 && i <= 34) {
      appendNumber = i - 25;
      labels.push(String.fromCharCode(65 + offset) + appendNumber);
    } else if (i > 33) {
      offset = Math.floor((i - 26) / 10);
      appendNumber = i - (25 + (offset * 10));
      labels.push(String.fromCharCode(65 + offset) + appendNumber);
    } else {
      labels.push(String.fromCharCode(65 + i));
    }
  }
  return labels;
}

returns an array of strings / labels that can be used for charts. The format of the returned list is:

["A",..."Z",...,"A1","A2",...,"A10",..."Z10"]

the amount parameter determines how many elements will be generated. there is no check on the amount so in case the amount exceeds "Z10" you'll get strange labels with symbols in it.

If you wish to change it to the headers on excel documents for example, like continuous headers ["A",..."Z","A1",..."Z1","A2" ...] is really simple the change

function generateAlphaNumericLabels(amount) {
  var labels = [];
  for (var i = 0; i <= amount; i++) {     
      if (i > 25) {
        labels.push(String.fromCharCode(65 + (i % 26)) + Math.floor(i/26));
      } else {
        labels.push(String.fromCharCode(65 + i));
      }
  }
  return labels;
}