Issue with REST use to track manually visitor country


From a PHP script, I try to call the Piwik REST API:

$piwikREST = 'http://[myPiwikServer]/piwik.php?idsite=5&rec=1&url='.urlencode($_SERVER["REQUEST_URI"]).'&action_name='.urlencode('_test').'&_id=0201010101010101&rand='.rand(1, 32000).'&country=DE&token_auth=8689af8d5bfb8c4a32ba54cc293dc11d';


The fact is that data are not updated in the Visitor Country map.
My questions:
1/ Is the call to REST API is correct?
2/ Is somehthing wrong in my call as Visitor Country does not reflect
3/ Would there be another approache to track manually user country?

Thanks in advance for your help