Option Explicit
 
Const VK_ALT = &H12&
Const VK_TAB = &H9&
Const KEYEVENTF_KEYUP = &H2
 
Private Declare Sub keybd_event Lib "user32.dll" (ByVal bVk As Byte, ByVal _
  bScan As Byte, ByVal dwFlags As Long, ByVal dwExtraInfo As Long)
Private Declare Function GetForegroundWindow Lib "user32" () As Long
 
Dim handle As Long
 
Private Sub Command1_Click()
    keybd_event VK_ALT, 0, 0, 0
    keybd_event VK_TAB, 0, 0, 0
    keybd_event VK_TAB, 0, KEYEVENTF_KEYUP, 0
    keybd_event VK_ALT, 0, KEYEVENTF_KEYUP, 0
    DoEvents
    handle = GetForegroundWindow
    MsgBox CStr(handle) & " (HEX: " & Hex(handle) & ")"
End Sub

mfg
brave@heart

...bis zur unendlichkeit und noch viel weiter...