Isolating the Last Names
The only way to do this is to get the last names into a separate column and then base your sort on that column and not on the existing names. Make sure that the sorting column is right next to one of the existing columns in your worksheet so that Excel captures it as part of your list. You can always hide your sorting column.
There are several methods of isolating the last names. In this article we shall be discussing Flash Fill, Text to Columns, Find and Replace and Formulas. To make your life easy, try to make your text as regular as possible as most of these processes are about finding a space in the middle of a bit of text. Any double-barrelled names like Ann Marie, Jean Paul or Wynn Jones will be much easier to process if you substitute the space with a dash, like this: Ann-Marie, Jean-Paul or Wynn-Jones.