Code:

uses

  RichEdit;

procedure TForm1.Button1Click(Sender: TObject);

var

  fmt: TParaformat2;

begin

  FillChar(fmt, SizeOf(fmt), 0);

  fmt.cbSize := SizeOf(fmt);

  // The PARAFORMAT2 structure is used to set the numbering style.

// This is done through the following structure members:

fmt.dwMask := PFM_NUMBERING or PFM_NUMBERINGSTART or PFM_NUMBERINGSTYLE or

                PFM_NUMBERINGTAB;

      // Set the following values (bitwise-or them together) to identify

     // which of the remaining structure members are valid:

     // PFM_NUMBERING, PFM_NUMBERINGSTART, PFM_NUMBERINGSTYLE, and PFM_NUMBERINGTAB

fmt.wNumbering := 2;

      //0 no numbering or bullets

     //1 (PFN_BULLET) uses bullet character

     //2 Uses Arabic numbers (1, 2, 3, ...).

     //3 Uses lowercase letters (a, b, c, ...).

     //4 Uses uppercase letters (A, B, C, ...).

     //5 Uses lowercase Roman numerals (i, ii, iii, ...).

     //6 Uses uppercase Roman numerals (I, II, III, ...).

     //7 Uses a sequence of characters beginning with the Unicode

     //  character specified by the wNumberingStart member.

fmt.wNumberingStart := 1;

      //  Starting value for numbering.

fmt.wNumberingStyle := $200;

      // Styles for numbering:

     // 0 : Follows the number with a right parenthesis.  1)

     // $100 : Encloses the number in parentheses.       (1)

     // $200 : Follows the number with a period.          1.

     // $300 : Displays only the number.                  1

     // $400 : Continues a numbered list without applying the next number or bullet.

     // $8000 : Starts a new number with wNumberingStart.

fmt.wNumberingTab := 1440 div 4;

  // Minimum space between a paragraph number and the paragraph text, in twips

RichEdit1.Perform(EM_SETPARAFORMAT, 0, lParam(@fmt));

end;