To fill multiple lines of a TString object use the SetText property.  The null terminated string is a concatination of each line of text delimeted by a carriage return character #13 in between  For example the following statment:
      Listbox1.Items.SetText('aaaaa'#13'bbbbb'#13'ccccc')
will display the following in a listbox window:
      aaaaa
      bbbbb
      ccccc