Ti posto un modo di leggere il file excel in ADO:

codice:
    Dim cn As ADODB.Connection
    Dim RSXls As New ADODB.Recordset
    Set cn = New ADODB.Connection
    nomeexcel = "c:\prova.xls"
    With cn
        .Provider = "Microsoft.Jet.OLEDB.4.0"
        .ConnectionString = "Data Source=" & nomeexcel & ";" & _
    "Extended Properties=Excel 8.0;"
        .Open
   End With
   RSXls.Open "SELECT * FROM [Foglio1$]", cn, adOpenStatic
   'loop su tutte le righe del foglio excel   
   Do Until RSXls.EOF
    colonna0= RSXls(0)
    colonna1= RSXls(1)
    ....
    RSXls.MoveNext
  Loop
  RSXls.Close
  cn.Close
Spero sia chiaro, ciao.