You can use normalize-unicode($input, 'NFD') to convert the string to
decomposed normal form; the diacritics will then be present as separate
characters, which you can detect and remove using a regular expression -
probably the same regex that removes other unwanted characters.

Thank you very much and happy new year!
I suspected that there is such a function, but cound not find it.
--
Vladimir Nesterovsky
http://www.nesterovsky-bros.com