use warnings;
use strict;
use Template;

my $tt = Template->new();
my %data_href = (
                 fname => 'William',
                 lname => 'Shakespeare',
                 );

$tt->process( \*DATA, { data_href => \%data_href, } )
    or die $tt->error(), "\n";

__END__
My original template
====================
First name : [% data_href.fname %]
Last name  : [% data_href.lname %]