Select Code to Download

 (split(/\./,$_,3))[1] =~ /^(\d+)([A-Za-z]+)(\d+)$/; 
 [$_, $3, $months{$2}, sprintf("%02d", $1) ]

 (split(/\./,$_,3))[1] =~ /^(\d+)([A-Za-z]+)(\d+)$/ or die "improperly
+ formed data: $_";
 [$_, $3, $months{$2}, sprintf("%02d", $1) ]