Code:
Function UNDO(hWnd As Long)
    SendMessage hWnd, EM_UNDO, 0, 0
End Function

Function ToClip(hWnd As Long)
    SendMessage hWnd, WM_COPY, 0, 0
End Function

Function FromClip(hWnd As Long)
    SendMessage hWnd, WM_PASTE, 0, 0
End Function

Function CleanToClip(hWnd As Long)
    SendMessage hWnd, WM_CUT, 0, 0
End Function
Okay... I have some problems with these.

When I call...

Undo - Just selects all the text.
ToClip - Works, but see FromClip (copy command)
FromClip - Pastes it TWICE. Error might be in ToClip when using that, or CleanToClip while using that(paste command)
CleanToClip - Works, but has same side-effects as ToClip when pasting back (see From Clip) (cut command)