This might give you some ideas

VB Code:
  1. Dim oExcel As Excel.Application

  2.     Dim oBook As Excel.Workbook

  3.     Dim oSheet As Excel.Worksheet

  4.     

  5.     Set oExcel = New Excel.Application

  6.     Set oBook = oExcel.Workbooks.Open("C:\projects\testing.xls")

  7.     oExcel.Visible = True

  8.     

  9.     For Each oSheet In oBook.Worksheets

  10.         'assumes cell A23 is a valid date 

  11.         'The Sheet Name cannot contain the characters \ / ? * [ ]

  12.         oSheet.Name = Format$(oSheet.Cells(23, 1), "dd-MMM-yyyy") 

  13.     Next

  14.     

  15.     oBook.Close True

  16.     Set oBook = Nothing

  17.     

  18.     oExcel.Quit

  19.     Set oExcel = Nothing