[Zope] generating zope-ids from usernames

I want to generate a userid for a Zopeuser from the fullname the user enters. Is there a script around, which replaces all characters not allowed in ids especially the with a meaningfull equivalent ? For example ö (o umlaut) --> oe -- Mit freundlichen Grüßen Joachim Schmitz ...................................................................... AixtraWare eK ..Joachim Schmitz ..www.aixtraware.de ..t: +49-2464-8851 Hüsgenstr. 33a .....d-52457 Aldenhoven .............f: +49-2464-905163