Looking for a way to randomize font alternates

Thank you all for the information. Where Fontself is easy to use and an "in application"plug-in. (and works very well), it dosen't have alot of the options to code each glyph, as you create the font like some of the more expensive font creation software. Something to look into. I am going to play with the Indesign script. THX

Unfortunately the author is using the font in Photoshop but I am going to look into that  thank you 

To clarify, alternates use different Unicode codepoints to the canonical characters, typically somewhere in the U+E000–U+F8FF private use range. To insert alternate characters in AI using JSX, you need to know their codepoints.

e.g. OP might build a lookup table that maps the canonical A–Z, a–z, etc characters to their alternates. For each character in the original text, look up its alternate characters, pick one at random, and substitute:

var characterMap = {
  'A': 'A\ue001\ue002\ue003',
  'B': 'B\ue004\ue005\ue006',
  'C': ...
};

var oldText = someTextFrame.contents;

var newText = '';
for (var i = 0; i < oldText.length; i++) {
  var c = oldText[i];
  var alternates = characterMap[c];
  if (alternates) {
    c = alternates[Math.floor(Math.random() * alternates.length)];
  }
  newText += c;
}
someTextFrame.contents = newText;

FontForge is ugly but free and should suffice for examining the generated font’s glyph table to determine the alternates’ code points.