This property returns and sets the number of selected characters. In addition, you can use this property for tasks such as setting the insertion point, establishing an insertion range, selecting substrings in a control, or clearing text. For copy, cut, and paste operations, use SelLength in conjunction with the Clipboard object.
object.SelLength [= number]
The SelLength property is unavailable at design time. Setting SelLength less than 0 causes a run-time error.