I have a crossword helper program 'word' that will let you do this: '-a' specifies anagram and '-u' specifies a subset of the supplied letters, so I'd use it so:

  zen% word -ua dude
  de dud dude due dued Ed
  zen%
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The program always constructs a single regexp that matches the things it's searching for, in this case:

  /^(?:(?:([eu])(?!.*\1)|([d])(?!.*\2.*\2))+)\z/oi
[download]

Hugo