OFN_NOTESTFILECREATE top-level constant
The file is not created before the dialog box is closed. This flag should be specified if the application saves the file on a create-nonmodify network share. When an application specifies this flag, the library does not check for write protection, a full disk, an open drive door, or network protection. Applications using this flag must perform file operations carefully, because a file cannot be reopened once it is closed.
const OFN_NOTESTFILECREATE = 0x00010000;