Incorporate it into HTML::Template? Well, you do the DBI calls in your Perl code, then you pass the calculated value as a param to the template:

my $rc=$sth->execute...
my $tmpl=HTML::Template->new...
if ($rc==1) {
  my ($count)=$sth->fetchrow_array; # I only use this when fetching a 
+single value
                                    # otherwise I use fetchrow_hashref
  $tmpl->param(replycount=>$count);
}
... # lots more code, presumably
print $tmpl->output;
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