php 调用 C++ dll,该怎么解决

php 调用 C++ dll
动态库中要调用的函数

C/C++ code

<!--Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/-->extern "C" int __stdcall GameRegister(char* szSystemInfo, char *szRegCode, char *szLicense);

PHP代码

PHP code

<!--Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/--><?php $dw = new Com("DynamicWrapper");                $dw->Register("EducationGameRegister.dll", "GameRegister", 'i=sss', "f=s", "r=u");                                 $reg_code = "";                $ch = $dw->GameRegister("P2G9YFWGZW68G","2597367cea95b2cf0aace3bd5059c33e",&$reg_code);                                echo "Return Value：".$ch;                echo "Register Code：".$reg_code;                ?>

运行时出现下面的错误： 
Fatal error: Uncaught exception 'com_exception' with message 'Error [0x80070057] 参数不正确。 ' in D:\WAMP\WWW\index.php:11 Stack trace: #0 D:\WAMP\WWW\index.php(11): com->Register('EducationGameRe...', 'GameRegister', 'i=sss', 'f=s', 'r=l') #1 {main} thrown in D:\WAMP\WWW\index.php on line 11

初次接触PHP,大家帮我看一下，谢谢了！

------解决方案--------------------
原型要求参数是指针，而 com 是不能传递指针的
------解决方案--------------------
$ch = $dw->GameRegister("P2G9YFWGZW68G","2597367cea95b2cf0aace3bd5059c33e",$reg_code);
這樣試試