it seems then the solution will be to use PHP 5.6.33 alongisde 2008 R2 server.
the current connection method on the 2003 server is
<?php
$serverName = "server_name";
$connectionInfo = array( "Database"=>"dbname", "UID"=>"user", "PWD"=>"password");
$conn = sqlsrv_connect( $serverName, $connectionInfo );
if( $conn === false ) {
die( print_r( sqlsrv_errors(), true));
}
$sql = "select RIGHT(ld_filename, (CHARINDEX('\',REVERSE(ld_filename),0))-1) as filename, * from linked_documents where ld_id = '$ctsref'";
$stmt = sqlsrv_query( $conn, $sql );
if( $stmt === false) {
die( print_r( sqlsrv_errors(), true) );
}
while( $row = sqlsrv_fetch_array( $stmt, SQLSRV_FETCH_ASSOC) ) {
?>