Some important stuff from the DirectDraw DDK headers.

include/dciddi.h

+/* DCI driver interface */
+
+#ifndef __WINE_DCIDDI_H
+#define __WINE_DCIDDI_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* DCI Command Escape */
+#define DCICOMMAND	3075
+#define DCI_VERSION	0x0100
+
+#define DCICREATEPRIMARYSURFACE		1
+#define DCICREATEOFFSCREENSURFACE	2
+#define DCICREATEOVERLAYSURFACE		3
+#define DCIENUMSURFACE			4
+#define DCIESCAPE			5
+
+/* DCI Errors */
+#define DCI_OK		0
+
+
+typedef int DCIRVAL; /* DCI callback return type */
+
+/*****************************************************************************
+ * Escape command structures
+ */
+typedef struct _DCICMD {
+    DWORD dwCommand;
+    DWORD dwParam1;
+    DWORD dwParam2;
+    DWORD dwVersion;
+    DWORD dwReserved;
+} DCICMD,*LPDCICMD;
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif /* __WINE_DCIDDI_H */