FitText Property
True if Microsoft Word visually reduces the size of text typed into a cell so that it fits within the column width. Read/write Boolean.
Remarks
If the FitText property is set to True, the font size of the text is not changed, but the visual width of the characters is adjusted to fit all the typed text into the cell.
Example
This example sets the first cell in the selection to automatically fit typed text within its width.
Selection.Cells(1).FitText = True