excel怎么把单元格内某个字标红，其他字不变

alt+F11，打开宏编辑器运行如下代码：

Sub AAA()

    Dim R As Range, L As Long, S As String

    Application.ScreenUpdating = False

    S = "红"  '要标记的字符

    L = Len(S)

    For Each R In Selection

        If InStr(R, S) > 0 Then R.Characters(InStr(R, S), L).Font.Color = vbRed

    Next

    Application.ScreenUpdating = True

End Sub