I am not completely sure that I understand what you are trying to do. Some of this looks a bit overly complex. Why wouldn't you just use an Array of Array with all 3 parts that you need? Why does there need to be a hash at all?. A simple modification to your @excerpts creation code could be like this:

use warnings;
use Data::Dumper;


$fc = 'abcdfoofrobnicatebardefforspambazghi'; 

$re2 = qr/(fo.)(.*?)(ba.)/;

my @excerpts;
push @excerpts, [$1,$2,$3] while $fc =~ /$re2/g;

print Dumper \@excerpts;

# Simple iteration over the Array of Array (AoA)
# for each row break this down into names that make sense
# for your data, whatever they are.. use those names
# instead of indicies to process the data.

foreach my $rowref (@excerpts)
{
   my($namea,$nameb,$namec) = @$rowref;
   print "first=$namea second=$nameb third=$namec\n";
}

__END__

$VAR1 = [
          [
            'foo',
            'frobnicate',
            'bar'
          ],
          [
            'for',
            'spam',
            'baz'
          ]
        ];
first=foo second=frobnicate third=bar
first=for second=spam third=baz
[download]

Echoing stevieb's comment, it would help if you could manually create an example of the structure that you are trying to build. Or maybe back up a bit and explain how you intend to use the structure and we can suggest some possibilities?

Update: added how to use AoA to the code above.