Example -
Below code will open an excel sheet in QTP
filepath = "C:\Sai\Report.xlsx"
Set objExcel = CreateObject("Excel.Application")
objExcel.Visible = True
Set Wb = objExcel.Workbooks.Open(filepath)
'After you get reference to workbook, you can access sheets inside it and values as well
e.g.
Wb.worksheets(1).Cells(1,1).Value = "Scenario Id"
Wb.worksheets(1).Cells(1,2).Value = "Secnario Name"
Wb.worksheets(1).Columns(1).ColumnWidth = 10