By default, the AutoSearch property is True. The auto-search feature is is commonly known as incremental search. An incremental search begins searching as soon as you type the first character of the search string. As you type in the search string, the control selects the item  ( and highlight the portion of the string that match where the string (as you have typed it so far) would be found. The control supports 'starts with' or 'contains' incremental search as described in the AutoSearch property of the Column object. Use the ExpandOnSearch property to expand items while user types characters in the control. Use the MarkSearchColumn property to specify whether the control draws a rectangle around the searching column.

The control highlights the characters as the user types them: