在access中使用sendkeys有时会导致数字或大写指示灯无故熄灭，故安全的办法还是使用API函数。
但最好尽量少用sendkeys,因为有时因为键误操作导致错误。
作者：Dev Ashish
'******** Code Start ***********
      ' Declare Type for API call:
      Private Type OSVERSIONINFO
        dwOSVersionInfoSize As Long
        dwMajorVersion As Long
        dwMinorVersion As Long
        dwBuildNumber As Long
        dwPlatformId As Long
        szCSDVersion As String * 128   '  Maintenance string for PSS usage
      End Type

      ' API declarations:
      Private Declare Function GetVersionEx Lib "Kernel32" _
         Alias "GetVersionExA" _
         (lpVersionInformation As OSVERSIONINFO) As Long

      Private Declare Sub keybd_event Lib "user32" _
         (ByVal bVk As Byte, _
          ByVal bScan As Byte, _
          ByVal dwflags As Long, ByVal dwExtraInfo As Long)

      Private Declare Function GetKeyboardState Lib "user32" _
         (pbKeyState As Byte) As Long

      Private Declare Function SetKeyboardState Lib "user32" _
         (lppbKeyState As Byte) As Long

      ' Constant declarations:
      Const VK_NUMLOCK = &H90
      Const VK_SCROLL = &H91
      Const VK_CAPITAL = &H14
      Const KEYEVENTF_EXTENDEDKEY = &H1
      Const KEYEVENTF_KEYUP = &H2
      Const VER_PLATFORM_WIN32_NT = 2
      Const VER_PLATFORM_WIN32_WINDOWS = 1

Function IsCapsLockOn() As Boolean
        Dim o As OSVERSIONINFO

        o.dwOSVersionInfoSize = Len(o)
        GetVersionEx o
        Dim keys(0 To 255) As Byte
        GetKeyboardState keys(0)
        IsCapsLockOn = keys(VK_CAPITAL)
End Function

Sub ToggleCapsLock()
        Dim o As OSVERSIONINFO

        o.dwOSVersionInfoSize = Len(o)
        GetVersionEx o
        Dim keys(0 To 255) As Byte
        GetKeyboardState keys(0)

        If o.dwPlatformId = VER_PLATFORM_WIN32_WINDOWS Then  '=====Win95
        'Toggle capslock
            keys(VK_CAPITAL) = Abs(Not keys(VK_CAPITAL))
            SetKeyboardState keys(0)
        ElseIf o.dwPlatformId = VER_PLATFORM_WIN32_NT Then   '=====WinNT
          'Simulate Key Press>
            keybd_event VK_CAPITAL, &H45, KEYEVENTF_EXTENDEDKEY Or 0, 0
          'Simulate Key Release
            keybd_event VK_CAPITAL, &H45, KEYEVENTF_EXTENDEDKEY _
               Or KEYEVENTF_KEYUP, 0
        End If
End Sub

Function IsNumLockOn() As Boolean
        Dim o As OSVERSIONINFO
       
        o.dwOSVersionInfoSize = Len(o)
        GetVersionEx o
        Dim keys(0 To 255) As Byte
        GetKeyboardState keys(0)
        IsNumLockOn = keys(VK_NUMLOCK)
End Function

Sub ToggleNumLock()
        Dim o As OSVERSIONINFO
               
        o.dwOSVersionInfoSize = Len(o)
        GetVersionEx o
        Dim keys(0 To 255) As Byte
        GetKeyboardState keys(0)

          If o.dwPlatformId = VER_PLATFORM_WIN32_WINDOWS Then  '=====Win95
                keys(VK_NUMLOCK) = Abs(Not keys(VK_NUMLOCK))
                SetKeyboardState keys(0)
          ElseIf o.dwPlatformId = VER_PLATFORM_WIN32_NT Then   '=====WinNT
          'Simulate Key Press
            keybd_event VK_NUMLOCK, &H45, KEYEVENTF_EXTENDEDKEY Or 0, 0
          'Simulate Key Release
            keybd_event VK_NUMLOCK, &H45, KEYEVENTF_EXTENDEDKEY _
               Or KEYEVENTF_KEYUP, 0
          End If
       
End Sub

Function IsScrollLockOn()
        Dim o As OSVERSIONINFO
       
        o.dwOSVersionInfoSize = Len(o)
        GetVersionEx o
        Dim keys(0 To 255) As Byte
        GetKeyboardState keys(0)
        IsScrollLockOn = keys(VK_SCROLL)
End Function

Sub ToggleScrollLock()
        Dim o As OSVERSIONINFO
       
        o.dwOSVersionInfoSize = Len(o)
        GetVersionEx o
        Dim keys(0 To 255) As Byte
        GetKeyboardState keys(0)
        If o.dwPlatformId = VER_PLATFORM_WIN32_WINDOWS Then  '=====Win95
            keys(VK_SCROLL) = Abs(Not keys(VK_SCROLL))
            SetKeyboardState keys(0)
        ElseIf o.dwPlatformId = VER_PLATFORM_WIN32_NT Then   '=====WinNT
            'Simulate Key Press
            keybd_event VK_SCROLL, &H45, KEYEVENTF_EXTENDEDKEY Or 0, 0
            'Simulate Key Release
            keybd_event VK_SCROLL, &H45, KEYEVENTF_EXTENDEDKEY Or KEYEVENTF_KEYUP, 0
        End If
End Sub

Sub mySendKeys(sKeys As String, Optional bWait As Boolean = False)
Dim bNumLockState As Boolean
Dim bCapsLockState As Boolean
Dim bScrollLockState As Boolean
    bNumLockState = IsNumLockOn()
    bCapsLockState = IsCapsLockOn()
    bScrollLockState = IsScrollLockOn()
    SendKeys sKeys, bWait
    If IsNumLockOn() <> bNumLockState Then
        ToggleNumLock
    End If
    If IsCapsLockOn() <> bCapsLockState Then
        ToggleCapsLock
    End If
    If IsScrollLockOn() <> bScrollLockState Then
        ToggleScrollLock
    End If
End Sub

Function fSendKeys(sKeys As String, Optional bWait As Boolean = False)
' Function to make it callable from macros
    mySendKeys sKeys, bWait
End Function
'******** Code End ***********