compañero te dejo un ejemplo que aplica algunos formatos
Código Delphi
[-]ExcelApplication1.Connect;
ExcelApplication1.Visible[0] := true;
ExcelWorkbook1.ConnectTo(ExcelApplication1.Workbooks.Add(EmptyParam,0));
ExcelWorksheet1.ConnectTo(ExcelApplication1.Sheets[1] as _WorkSheet);
excelworksheet1.Range['A1','D1'].MergeCells :=true;
excelworksheet1.Range['A3','D3'].MergeCells :=true;
excelworksheet1.Range['A1','D3'].HorizontalAlignment:=xlHAlignCenter ;
excelworksheet1.Range['c4','c4'].HorizontalAlignment:=xlHAlignRight;
excelworksheet1.Range['C1','C1'].ColumnWidth :=80;
excelworksheet1.cells.item[1,1].value2:='CODEKA COMERCIALIZADORA SA DE CV';
excelworksheet1.cells.item[3,1].value2:='Lista de Productos para Verificar Existencia';
excelworksheet1.cells.item[4,3].value2:= 'Fecha:';
excelworksheet1.cells.item[4,4].formula:= date();
excelworksheet1.Range['A5','D5'].interior.Color:=33023 ;
excelworksheet1.Range['A5','D5'].Borders.LineStyle:= xlContinuous;
excelworksheet1.Range['A5','D5'].Borders.Weight:= 1;
excelworksheet1.Range['A5','D5'].Borders.Color:= clblack;
espero te sirva
