Heres some code I use to connect to an excel data range  :-

Using m_connexcel As OleDbConnection = New OleDbConnection(String.Format("Provider=Microsoft.Jet.OLEDB.4.0;" & _
                                                                  "Data Source={0};" & _
                                                                  "Extended Properties=""Excel 8.0;HDR=NO""", SPREADSHEET_NAME))
                        m_connexcel.Open()
                        Using cmd As OleDbCommand = New OleDbCommand(String.Format("SELECT  * FROM [{0}]", DATARANGE), m_connexcel)
                            Using oRDR As OleDbDataReader = cmd.ExecuteReader
                                While (oRDR.Read)
                                   If Not oRDR.IsDBNull(oRDR.GetOrdinal("F1")) Then
                                      MsgBox(oRDR.GetString(oRDR.GetOrdinal("F1")))
                                   End If
                               End While
                            End Using
                        End Using
                        m_connexcel.Close()
End Using

Set 'HDR' in the connection string to 'YES' if you want to use the first row as the field names, otherwise the fields will be called
F1, F2, F3 etc...