In the Field dialog box, Field Category list, select Objects.
In Field Names, select Formula.
To enter a formula, do one of the following:
Click Average, Sum, or Count. The Field dialog box closes temporarily. To specify a range, click inside the first and the last cell. The result is appended to the formula.
Click Cell. The Field dialog box closes temporarily. Select a cell in a table in the drawing. The cell address is appended to the formula.
(Optional) Select a format and a decimal separator.
Click OK.
To save your changes and exit the editor, enter q (Quit).