To create a rich edit control, call the CreateWindowEx function, specifying the rich edit window class. If you are using rich edit 1.0 (RICHED32.DLL), specify "RichEdit" for the window class parameter. If you are using rich edit version 2.0 (RICHED20.DLL), specify RICHEDIT_CLASS for the window class parameter.
Rich edit controls support most of the window styles used with edit controls as well as additional styles. You should specify the ES_MULTILINE window style if you want to allow more than one line of text in the control.