Copiar varios arquivos em um Unico.

c:\>copy arq1.txt+arq2.txt+arq3.txt arq123.txt

var
  S1, S2, S3, S123 : TStringList;
begin
  S1 := TStringList.Create;
  S2 := TStringList.Create;
  S3 := TStringList.Create;
  S123 := TStringList.Create;

  S1.LoadFromFile(´arq1.txt´);
  ...
  S123.Text := S1.Text + S2.Text + S3.Text;
  S123.SaveToFile(´arq123.txt´);
  S1.Free;
  S2.Free;
  ...