Select characters in a cell or cell range that you'd like to format. On the Home tab, in
the Font group, click the Font Settings dialog box launcher. Press CTRL+1. Under
Effects, check the Superscript or Subscript box, and click OK.
OR
// Short cut command to apply x square in excel
Press Alt + 0178
To set sequence of Number in Excel Automatically
In the first cell of the range that you want to number, type =ROW(A1).
The ROW function returns the number of the row that you reference. For example, =ROW(A1) returns the number 1.
Drag the fill handle Fill handle across the range that you want to fill.