my $string = 'abcdefghijk'; 
my %match = (bc => "Michelangelo", efg => "Raffaello",de => "Caravaggio",ijk => "Tintoretto",hij=>"Leonardo",);

foreach $art (keys %match){
    print "this is INDEX $art =>",join(',',$match{$art}),"\n", if index my $tring,$art;
    }