Thanks for your suggestion.
This does not solve my problem, unfortunately. I have found that the decode function in the Encode module should be able to do the job. 
use Encode;
print decode('utf8', "\xC3\xA5");

[download]
This prints the character I need.
The problem now is:
How to go from %C3%A5 etc. to \xC3\xA5?
I tried 
use Encode;
$_='%C3%A5';
 s/%/\\x/g;
eval { $_=$_};
print decode('utf8', $_);

[download]
but it does not work as expected. :-)
This was actually solved in the previous post by graff.

In reply to Re^4: javascript encodeURI() -> perl uri_unescape_utf8() ? by nkropols
in thread javascript encodeURI() -> perl uri_unescape_utf8() ? by nkropols

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