Poniżej przykład wywołania Open Dialog Box z Common Dialog Box
http://msdn.microsoft.com/en-us/library/windows/desktop/ms646829(v=vs.85).aspx#open_file
OPENFILENAME ofn; // common dialog box structure
char szFile[260]; // buffer for file name
HWND hwnd; // owner window
HANDLE hf; // file handle
// Initialize OPENFILENAME
ZeroMemory(&ofn, sizeof(ofn));
ofn.lStructSize = sizeof(ofn);
ofn.hwndOwner = hwnd;
ofn.lpstrFile = szFile;
// Set lpstrFile[0] to '\0' so that GetOpenFileName does not
// use the contents of szFile to initialize itself.
ofn.lpstrFile[0] = '\0';
ofn.nMaxFile = sizeof(szFile);
ofn.lpstrFilter = "All\0*.*\0Text\0*.TXT\0";
ofn.nFilterIndex = 1;
ofn.lpstrFileTitle = NULL;
ofn.nMaxFileTitle = 0;
ofn.lpstrInitialDir = NULL;
ofn.Flags = OFN_PATHMUSTEXIST | OFN_FILEMUSTEXIST;
// Display the Open dialog box.
if (GetOpenFileName(&ofn)==TRUE)
{
hf = CreateFile(ofn.lpstrFile, //Open the file
GENERIC_READ,
0,
(LPSECURITY_ATTRIBUTES) NULL,
OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL,
(HANDLE) NULL);
//Rest of the code hire
}