translate unicode chars hexadecimal encoded to iso-8859-1

Hi,

I'm trying to translate utf8 char encoded into a hexadecimal code, i
don't success with it. I know to translate hexa to ascii with
chr(hex($letter)) , i know to use Encode module to translate utf8 to
iso-8859 but i don't success to translate the hexa code to iso
enconding.
I get by internet post method a XML that it has some letter in utf8.
The problem is that the internet translate them to hexa encoding then i
get something like this %D7%A9 . I need to tranlaste it to something i
can read in the shell or editor.

thanks!
by!