function QwertyToRUS(Ch: Char): Char;
const
  CEnglish = $0409;
  CRussian = $0419;
  CShiftMask = $0100;
  CCtrlMask  = $0200;
  CAltMask   = $0300;
var
  VkKey: SmallInt;
  Res: LongInt;
  LStates: TKeyboardState;
begin
  VkKey := VkKeyScan(Ch);
  FillChar(LStates[0], Length(LStates) * SizeOf(LStates[0]), 0);
  if VkKey and CShiftMask = CShiftMask then
    LStates[VK_SHIFT] := $FF;
  if VkKey and CCtrlMask = CCtrlMask then
    LStates[VK_CONTROL] := $FF;
  if VkKey and CAltMask = CAltMask then
    LStates[VK_MENU] := $FF;

  Res := ToUnicodeEx(VkKey, 0, LStates, @Result, 1, 0, CRussian);

  if Res = 0 then
    Result := Ch
  else if Res < 0 then
    raise Exception.Create('The specified key is a dead key')
  else if Res > 1 then
    raise Exception.Create('The dead-key ...... a single character');
end;