请教MoveDown(VARIANT* Unit, VARIANT* Count, VARIANT* Extend)中的Extend 在那里定义的

请问MoveDown(VARIANT* Unit, VARIANT* Count, VARIANT* Extend)中的Extend 在那里定义的?
MoveDown(VARIANT*   Unit,   VARIANT*   Count,   VARIANT*   Extend)

这个函数中的参数Extend是在哪个word的头文件中定义的,怎么使用?被它搞背了!

------解决方案--------------------

oaid.h
typedef tagVARIANT VARIANT
struct tagVARIANT
{
union
{
struct __tagVARIANT
{
VARTYPE vt;
WORD wReserved1;
WORD wReserved2;
WORD wReserved3;
union
{
LONG lVal;
BYTE bVal;
SHORT iVal;
FLOAT fltVal;
DOUBLE dblVal;
VARIANT_BOOL boolVal;
_VARIANT_BOOL bool;
SCODE scode;
CY cyVal;
DATE date;
BSTR bstrVal;
IUnknown __RPC_FAR *punkVal;
IDispatch __RPC_FAR *pdispVal;
SAFEARRAY __RPC_FAR *parray;
BYTE __RPC_FAR *pbVal;
SHORT __RPC_FAR *piVal;
LONG __RPC_FAR *plVal;
FLOAT __RPC_FAR *pfltVal;
DOUBLE __RPC_FAR *pdblVal;
VARIANT_BOOL __RPC_FAR *pboolVal;
_VARIANT_BOOL __RPC_FAR *pbool;
SCODE __RPC_FAR *pscode;
CY __RPC_FAR *pcyVal;
DATE __RPC_FAR *pdate;
BSTR __RPC_FAR *pbstrVal;
IUnknown __RPC_FAR *__RPC_FAR *ppunkVal;
IDispatch __RPC_FAR *__RPC_FAR *ppdispVal;
SAFEARRAY __RPC_FAR *__RPC_FAR *pparray;
VARIANT __RPC_FAR *pvarVal;
PVOID byref;
CHAR cVal;
USHORT uiVal;
ULONG ulVal;
INT intVal;
UINT uintVal;
DECIMAL __RPC_FAR *pdecVal;
CHAR __RPC_FAR *pcVal;
USHORT __RPC_FAR *puiVal;
ULONG __RPC_FAR *pulVal;
INT __RPC_FAR *pintVal;
UINT __RPC_FAR *puintVal;
struct __tagBRECORD
{
PVOID pvRecord;
IRecordInfo __RPC_FAR *pRecInfo;
} __VARIANT_NAME_4;
} __VARIANT_NAME_3;
} __VARIANT_NAME_2;
DECIMAL decVal;
} __VARIANT_NAME_1;
};
------解决方案--------------------
楼上得强!
Variant is a C++ implementation of the Object Pascal intrinsic type Variant.

Header

sysvari.h

Description

The Variant type is capable of representing values that change type dynamically. Whereas a variable of any other type is statically bound to that type, a variable of the Variant type can assume values of differing types at run-time. The Variant type is most commonly used in situations where the actual type to be operated upon varies or is unknown at compile-time. While variants offer great flexibility, they also consume more memory than regular variables, and operations on variants are substantially slower than operations on statically typed values.