in reply to problematice metashar regexp
One of the things that may go wrong is that you substitute in the result of a substitution. Consider the first character 'h', it's replaced by '^', but '^' can in turn be replaced by '~', depending on the order of the keys, something you don't control in a hash. Maybe this effect is intentional, but if not, it could be the source of your problem. If so, replace the global substitution by a while over the characters of the string.
Hope this helps, -gjb-
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