Compiler construction 为什么dev.dmCopies返回编译器错误？

我正在做一个在信封上打印地址的程序。作为程序的一部分，我需要更改一些默认打印设置，例如纸张大小。为此，我使用下面列出的DocumentProperties代码

 HANDLE hPrinter;
 char pDevice[35];
 strcpy(pDevice,"Test");
 PRINTDLG pd;
 string name;
 ofstream print;
 memset( &pd, 0, sizeof( pd ) );
 pd.lStructSize = sizeof( pd );
 pd.Flags = PD_RETURNDC;
 OpenPrinter(pDevice,&hPrinter,NULL);
 DWORD dwNeeded = ::DocumentProperties(NULL, hPrinter, pDevice, NULL, NULL, 0);
 cout << dwNeeded << endl;
 PDEVMODE  dev = (PDEVMODE)::malloc(dwNeeded);
 cout << "2" << endl;
 DocumentProperties(NULL, hPrinter, pDevice, dev, NULL,  DM_OUT_BUFFER);
 cout << "3" << endl;
 cout << "3b" << endl;        
 dev.dmFields |= DM_COPIES;   // define the number of copies as 3
 cout << "4" << endl;
 dev.dmCopies = 3; // define, which field was changed

 cout << "5" << endl;
 DocumentProperties(NULL,  hPrinter, pDevice,  dev, dev, DM_IN_BUFFER  | DM_OUT_BUFFER);   
 cout << "set" << endl;`

我已经尝试将dev.dmCopies和dev.dmFields更改为dev->dmCopies和dev->dmFields，但是程序刚到3b，就退出了。根据MSDN，这些字段应该可以工作，所以我不知道为什么会出现这些错误：

main.cpp:98:10: error: request for member 'dmFields' in 'dev', which is of non-class type 'DEVMODEA*'
main.cpp:100:19: error: request for member 'dmCopies' in 'dev', which is of non-class type 'DEVMODEA*'`