I advice you not to do it. You user knows better when to switch the keyboard layout or input language. Also, why do you thing the key is Alt+Shift? Different options are available to the user.
If you really want to do this ugly thing, I know the only one way: to use Windows API
SendInput
. It simulates keyboard or mouse input on low-level; see
http://msdn.microsoft.com/en-us/library/ms646310(v=vs.85).aspx[
^].
Don't do it.
—SA