- Please open file sites/all/modules/custom/md_slider/templates/front/theme.front.inc, from line 197 to line 205

replace

if (strpos($link['value'], 'http') === FALSE && strpos($link["value"], "#") !== 0){
$url = parse_url($link['value']);
$options = array();
$options['absolute'] = TRUE;
if (isset($url['fragment']))
$options['fragment'] = $url['fragment'];

$variables["link"] = url($url['path'], $options);
  }

with

if (strpos($link['value'], 'http') === FALSE && strpos($link["value"], "#") !== 0){
$url = drupal_parse_url($link['value']);
$options = array();
$options['absolute'] = TRUE;
if (isset($url['fragment']))
$options['fragment'] = $url['fragment'];
if (isset($url['query'])) {
$options['query'] = $url['query'];
}

$variables["link"] = url($url['path'], $options);
  }

and just need to input lander?utm_term=test instead of mysite.org/lander?utm_term=test