use HTML::Template::Compiled;
my $htct = <<'HTML';
<b>Blah ist <?= zweiunvierzig ?></b>
HTML
my $htc = HTML::Template::Compiled->new(
    tagstyle => [qw/+php/],
    scalarref => \$htct,
);
$htc->param(zweiunvierzig => 42);
print $htc->output;