So this will extract the url in the form you want, as $url
:
$myArray = array(
'url' => 'url=http://some.website.com:8080/SASStoredProcess/do?_username=user-123&_password=passwd&_program=%2FUtilisateurs%2FDARTIES3-2012%2FMon+dossier%2Fanalyse_dc&annee=2012&ind=V&_action=execute',
'otherKey' => 'otherValue'
);
parse_str($myArray['url']);
echo $url;
You will need to decide where it needs to go next and how you get it there.