The problem is that when you write $string =~ s/[אבגדהו]/a/; the accented characters are in Mac encoding, not in UTF-8.So they never match in the string.

You should be able to fix this problem using Unicode::Map8 or maybe, I am not (yet!) familiar with it, Encode, which will be part of the core in 5.8.0.

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The Error Message is GOD - MJD