Range.WrapText (Excel)

Returns or sets a Variant value that indicates if Microsoft Excel wraps the text in the string.

This property returns True if text is wrapped in all cells within the specified range, False if text is not wrapped in all cells within the specified range, or Null if the specified range contains some cells that wrap text and other cells that don't. Microsoft Excel will change the row height of the range, if necessary, to accommodate the text in the range.

ActiveCell.WrapText = True