Custom string context substitution

Hi,

I set an argument passed to the view inside a panel as a string (because it's multi-word).
I also need to use that argument in the page title but with first letters of words uppercased.
So, I modified the file ctools/plugins/contexts/string.inc to make this string substitution available.

$plugin = array(
  'title' => t('String'),
  'description' => t('A context that is just a string.'),
  'context' => 'ctools_context_create_string',
  'keyword' => 'string',
  'no ui' => TRUE,
  'context name' => 'string',
  'convert list' => array(
    'raw' => t('Raw string'),
    'html_safe' => t('HTML-safe string'),
	'uppercase_words_HTML_safe' => t('HTML-safe string, first letters uppercased'),
  ),
  'convert' => 'ctools_context_string_convert',
  'placeholder form' => array(
    '#type' => 'textfield',
    '#description' => t('Enter the string for this context.'),
  ),
);

function ctools_context_string_convert($context, $type) {
  switch ($type) {
    case 'raw':
      return $context->data;
    case 'html_safe':
      return check_plain($context->data);
    case 'html_safe':
      return ucwords(str_replace("-", " ", check_plain($context->data)));
  }
}

This works, but I like to avoid hacking core files whenever possible.

Is there a way (hook or something) to put this transformation in a custom module where all of my other customizations reside, thus avoiding hacking core ctools files?

Thank you.