You are right: as far as I know, there is no other tool, which can produce regular expressions for different languages. (Until now I thought such a feature would be useless.)
Especially for Perl-compatible expressions there is a great tool at:http://weitz.de/regex-coach
The Regex Coach is a graphical application for Windows which can be used to experiment with (Perl-compatible) regular expressions interactively. It has the following features:
It shows whether a regular expression matches a particular target string.
It can also show which parts of the target string correspond to captured register groups or to arbitrary parts of the regular expression.
It can "walk" through the target string one match at a time.
It can simulate Perl's split and s/// (substitution) operators.
It tries to describe the regular expression in plain English.
It can show a graphical representation of the regular expression's parse tree.
It can single-step through the matching process as performed by the regex engine.
Everything happens in "real time", i.e. as soon as you make a change somewhere in the application all other parts are instantly updated.
You also may have a look at my TextTransformer at:http://www.texttransformer.com
There is a free regex test dialog for POSIX regular expressions integrated, which shows all sub-expressions and what was matched by them. In contrast to a Perl regex a POSIX regex always matches the longest possible string. Using this criterion, TextTransformer produces complete parsers and translators. E.g. you could make a parser for regular expressions of one language and translate it into expressions of another language.
If you or anybody else would make such a thing, and let me publish it onhttp://www.texttransformer.org
I would spend him a free standard version of TextTransformer. But caution: this is not so easy.