You can determine which character is closest to the specified point in an edit control by sending the EM_CHARFROMPOS message. The message returns the character index and line index of the character nearest the point. Similarly, you can determine the client coordinates of the specified character in an edit control by sending the EM_POSFROMCHAR message. You specify the index of a character and the message returns the x- and y-coordinates of the upper-left corner of the character.