Non andrebbe bene, in quanto mi metterebbe selected a tante opzioni quanti sono i valori dell'array, mentre ovviamente il selected va solo su un'opzione.
Ho però risolto il problema e posot il codice, dovesse servire a qualcuno.
	Codice PHP:
	
function SELECTED($firstVal, $secondVal){
                  if($firstVal == $secondVal){
                 $result = " SELECTED";
                  return $result;
                }
                }
                            
                            $conn = mysql_connect(DB_SERVER, DB_SERVER_USERNAME, DB_SERVER_PASSWORD);
                if (!$conn){
                  die("Errore: " . mysql_error());
              }    
                mysql_select_db(DB_DATABASE, $conn);
                            
                            $get_existing_data = tep_db_query("SELECT * FROM " . TABLE_EVIDENZA . " ORDER BY pos LIMIT " . IN_EVIDENZA_LIST_QUANTITY . "");
                            
                            while($posizioni = tep_db_fetch_array($get_existing_data)){
                                $array_posizioni[] = $posizioni['id_prod'];
                            }
                            
                            $get_data = tep_db_query("SELECT " . TABLE_PRODUCTS . ".products_id, " . TABLE_PRODUCTS . ".products_status, " .
                                                                             "" . TABLE_PRODUCTS_DESCRIPTION . ".products_name FROM " . TABLE_PRODUCTS . " " . 
                                                                             "INNER JOIN " . TABLE_PRODUCTS_DESCRIPTION . " ON " . 
                                                                             "(" . TABLE_PRODUCTS . ".products_id = " . TABLE_PRODUCTS_DESCRIPTION . ".products_id) " .
                                                                             "WHERE " . TABLE_PRODUCTS . ".products_status = 1 " .
                                                                             "ORDER BY " . TABLE_PRODUCTS_DESCRIPTION . ".products_name");
                            
                            while($row = tep_db_fetch_array($get_data)){
                                
                                    $array_products[$row[products_id]] = $row[products_name];
                                
                                }
                                
                                mysql_close($conn);
                            
                            for($i = 1; $i<=IN_EVIDENZA_LIST_QUANTITY; $i++){
                            
                                print ("<select name=\"select" . $i . "\">\n");
                                
                                  foreach($array_products as $key => $value){
                                      print ("<option value=\"" . $key . "\"" . SELECTED($key, $array_posizioni[$i-1]) . ">" . $value . "</option>\n");
                                  }
                                
                                print ("</select>
\n");
                            }