вместо SendKeys, вы можете попробовать API-функцию keybd_event
Private Declare Sub keybd_event Lib "user32.dll" (ByVal bVk As Byte, _
ByVal bScan As Byte, ByVal dwFlags As Integer, ByVal dwExtraInfo As Integer)
Private Const kbdDown = 0
Private Const kbdUp = 2
Private Sub SendKey(ByVal Key As Byte)
Call keybd_event(Key, 0, kbdDown, 0)
Call keybd_event(Key, 0, kbdUp, 0)
End Sub
Код ключа Print-Key - 42 (0x2A)