If you don't mind loosing the numbers at the end of some of the fields (or at least storing them elsewhere) you could just use a split 
use strict;

my $str = <<TXT;
Total index                                              B50001
 Crude processing (capacity)                             B5610C
 Primary & semifinished processing (capacity)            B562A3C
 Finished processing (capacity)                          B5640C
 Manufacturing ("SIC")                                   B00004
  Manufacturing (NAICS)                                  GMF
   Durable manufacturing (NAICS)                         GMFD
    Wood product                                         G321         
+    321
    Nonmetallic mineral product                          G327         
+    327
    Primary metal                                        G331         
+    331
     Iron and steel products                             G3311A2      
+    3311,2
    Fabricated metal product                             G332         
+    332
    Machinery                                            G333         
+    333
TXT

my(%hash, %numbers);
for(split "\n" => $str) {
  my @fields = reverse split;
  $numbers{$fields[1]} = shift @fields
    if $fields[0] =~ /\d(?:,\d+)?/;
  $hash{$fields[0]} = join ' ' => reverse @fields[1 .. $#fields];
}

my $code = 'GMF';

print "$code: $hash{$code}.\n";

__output__

GMF: Manufacturing (NAICS).

[download]
So that should give you the hash you want.
HTH

_________
broquaint

In reply to Re: Help me write a good reg-exp for this text by broquaint
in thread Help me write a good reg-exp for this text by waxmop

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