use HTML::Entities qw( encode_entities );

my $url = 'http://www.somedomain.com/index.cgi?page=home&var=1&no=2&so=forth&so=on';

my $h_url = encode_entities($url);
print(qq{...<a href="$h_url">...</a>...};

##</code><code>##

...<a href="[% url | html %]">...</a>...