如何在delphi5中实现对word文档页眉的设置？

我这有一个对当前页面的设置代码

var  

mmm,nnn,aaa:OleVariant;

begin

    mmm:=wdLine;
    nnn:=1;
    aaa:=wdFieldPage;
    WordApp.ActiveWindow.ActivePane.View.SeekView :=wdSeekCurrentPageHeader ;
    WordApp.Selection.Move(mmm,nnn);
    WordApp.Selection.ParagraphFormat.Alignment := wdAlignParagraphCenter;

    WordApp.Selection.InsertAfter('第');
    mmm:=wdCharacter;
    WordApp.Selection.Move(mmm,nnn);
    WordApp.Selection.Fields.Add(WordApp.Selection.Range,aaa,mmm,nnn);
    aaa:=wdFieldNumPages;
    WordApp.Selection.InsertAfter('页/第');
    WordApp.Selection.Move(mmm,nnn);
    WordApp.Selection.Fields.Add(WordApp.Selection.Range,aaa,mmm,nnn);

    WordApp.Selection.InsertAfter('页');
    WordApp.ActiveWindow.ActivePane.View.SeekView := wdSeekMainDocument;

end;

可是只能修改第一页的，怎么修改后面的页面的页眉？