My appreciation to Beth, who gave me a clue for moving this forward. Here is the code I finally used to achieve me end:

  my @loop_data;
  my $phone_lines;
  while (my $phone = $sth->fetchrow_hashref()){
    my $name = 'group_action_' . $phone->{'phone_number_id'};
    my $this_phone_line = $phone_line;
    my $links = $self->_get_links_for_phone_list($phone->{'phone_numbe
+r_id'});
    $this_phone_line =~ s/CHECKBOX/<tmpl_var field-$name>/;
    $this_phone_line =~ s/FNAME/$phone->{'fname'}/;
    $this_phone_line =~ s/LNAME/$phone->{'lname'}/;
    $this_phone_line =~ s/EMAIL/$phone->{'email'}/;
    $this_phone_line =~ s/PHONE/$phone->{'phone'}/;
    $this_phone_line =~ s/LINKS/$links/;
    $phone_lines .= $this_phone_line . "\n";

    $form->field(
           name => $name,
          label => '',
           type => 'checkbox',
        options => [ ' ' ],
         sticky => 0,
                );

  }

  open('TEMPLATE_COMPILED','>',$template_compiled);
  open('TEMPLATE','<',$template);
  while(<TEMPLATE>){
    if(m/PHONE_LINE/){
      $_ =~ s/PHONE_LINE/$phone_lines/;
    }
    print TEMPLATE_COMPILED $_;
  }
  close('TEMPLATE');
  close('TEMPLATE_COMPILED');
[download]

I essentially built the template as I went; and as I created each of the form elements. Accumulated the elements into a scalar and then used a string substitution to stitch together a complete custom template that accomodated the data.

I don't think I will be creating that new module to extend HTML::Template at this time. But thanks anyway. And thank you Beth for pointing the way.