Wanted: safe codec for filenames

[Torsten Bronger]

Hallöchen!

I'd like to map general unicode strings to safe filename.  I tried
punycode but it is case-sensitive, which Windows is not.  Thus,
"Hallo" and "hallo" are mapped to "Hallo-" and "hallo-", however, I
need uppercase Latin letters being encoded, too, and the encoding
must contain only lowercase Latin letters, numbers, underscores, and
maybe a little bit more.  The result should be more legible than
base64, though.

Has anybody created such a codec already?

Tschö,
Torsten.

-- 
Torsten Bronger, aquisgrana, europa vetus
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