void SetPasswordChar( char ch );
ch
Specifies the character to be displayed in place of the character typed by the user. If ch is 0, the actual characters typed by the user are displayed.
Sets or removes a password character displayed in an edit control when the user enters text. When a password character is set, that character is displayed for each character the user types in.
This member function has no effect on a multiple-line edit control.
When the SetPasswordChar member function is called, CEdit will redraw all visible characters using the character specified by ch.
If the edit control is created with the ES_PASSWORD style, the default password character is set to an asterisk (*). This style is removed if SetPasswordChar is called with ch set to 0.
EM_SETPASSWORDCHAR