None.
SetFocusWin gives the keyboard focus to the window that was targeted with TargetWin, TargetChild, SendWin, etc.
It calls the Windows system command SetFocus.
<hotkey F1> <sendpc local> <TargetWin"My difficult background Window"> <TargetChild "Obscure control class"> <SetFocusWin> <text woot it worked>
SetForegroundWin SetActiveWin