VC里面操作EXCEL 怎样设置单元格的边框

VC里面操作EXCEL 怎样设置单元格的边框,如果有些单元格只设置上边框,或者设置下边框,怎么设置!?

COleVariant vtOptional((long)DISP_E_PARAMNOTFOUND,VT_ERROR),

vtTrue((short)TRUE),

vtFalse((short)FALSE);

_Application* ExcelApp = new _Application;

ExcelApp->CreateDispatch("excel.application");

//设置为显示

ExcelApp->SetVisible(TRUE);

//得到WorkBooks

Workbooks ExcelBooks = ExcelApp->GetWorkbooks();

Sheets ExcelSheets = ExcelBooks.Add(vtOptional);

_Workbook workBook;

_Worksheet workSheet;

Range range;

workBook.AttachDispatch(ExcelApp->GetApplication());

ExcelSheets=workBook.GetSheets();

workSheet = ExcelSheets.GetItem(COleVariant((short)1));

workSheet.Activate();

Range myallrange=workSheet.GetRange(COleVariant("A1"),COleVariant("D1"));

//myallrange.BorderAround(COleVariant((short)1),(long)2,(long)1,vtOptional);

myallrange.SetHorizontalAlignment(COleVariant((short)3));//居中

myallrange.Merge(COleVariant((short)1));//合并单元格

myallrange.SetValue(COleVariant("个人信息表"));