how to get references from imbricated capturing parenthesis ?

Hi everyone!

I'm trying to get references from a simple regular exepression like
this :

"a40d7412" =~ /(([[:xdigit:]]{2})*)/;

print "$1: <$2><$3><$4><$5>\n";


This prints :
a40d7412: <12><><><>

How to get all references and not the last one in the second
parenthesis pair ?
I'm STFW for 2 hours :-(

Thanks in advance.

.