+ character in a command line argument

Hi! I'm using PHP 4.3.1, IE 5.5, Win ME I'm trying to use php through DOS command line. Running the very basic script $argv = $_SERVER['argv']; var_dump($argv); I noticed that the command line arguments are split at a + character, even if between double quotes. for instance php test.php a+b or php test.php "a+b" both return 3 arguments, "test.php", "a" and "b". I don't know if it is a DOS or php problem (though if you name a file a+b.txt, the DOS command type a+b.txt runs correctly, which seems to exonerate DOS...). My questions are more practical : does anybody knows how to pass a + in an argument?? Are there other characters that are special in addition to " and + ?? Thanks in advance