A possible solution would be replacing:

if (is_null($aFields)) $aFields=array_keys(createFieldMap($iSurveyID,'full',true,false,$sLanguageCode));

with

if (is_null($aFields)) {
$questionFields=array_keys(createFieldMap($iSurveyID,'full',true,false,$sLanguageCode));
$attributeFields = array_keys(getTokenFieldsAndNames($iSurveyID, TRUE));
$aFields = array_merge($questionFields, $attributeFields);
}

in the function definition of export_responses_by_token (application/helpers/remotecontrol/remotecontrol_handle.php)
Since the export_responses function is nearly identical, this should also reflect this change.

Another solution could be an extra optional argument in the function call and roughly the same code:

function export_responses($sSessionKey, $iSurveyID, $sDocumentType, $sLanguageCode=null, $sCompletionStatus='all', $sHeadingType='code', $sResponseType='short', $iFromResponseID=null, $iToResponseID=null, $qFields = null, $aFields = null)

with something like:
if (is_null($aFields)) {
$aFields=array_keys(createFieldMap($iSurveyID,'full',true,false,$sLanguageCode));
}
if (is_null($qFields)) {
$qFields = array_keys(getTokenFieldsAndNames($iSurveyID, TRUE));
}
$fields = array_merge($aFields, $qFields);

(replacing all following $aFields bij $fields)