using System;
using System.Data;
using System.Diagnostics;
using System.ComponentModel;
using System.Collections.Generic;
using System.Data.OleDb;
 
 
public class ExcelSpreadsheet {
  private List<string> _worksheets = new List<string>();
  [Description( "Gets a list of worksheet names matching the DataSet table names." )]
  public  List<string> WorkSheets { get { return _worksheets; } }
 
  private DataSet _spreadsheet = new DataSet();
  [Description( "Gets a DataSet with each table representing one worksheet in the spreadsheet" )]
  public DataSet SpreadSheet { get { return _spreadsheet; } }
 
 
  // Disable the default constructor
  private ExcelSpreadsheet() { }
 
 
  public ExcelSpreadsheet( string filename ) {
    _spreadsheet = this.LoadSpreadsheet( filename, false );
  }
 
 
  public ExcelSpreadsheet( string filename, bool hasHeader ) {
    _spreadsheet = this.LoadSpreadsheet( filename, hasHeader );
  }
 
 
  /// <summary> Load the worksheet names </summary>
  private IEnumerable<string> GetWorksheets( OleDbConnection connection ) {
    try {
      DataTable schema = connection.GetOleDbSchemaTable(
        OleDbSchemaGuid.Tables
       , new object[] { null, null, null, "TABLE" } );
 
       foreach ( DataRow row in schema.Rows ) {
         _worksheets.Add( row["TABLE_NAME"].ToString() );
      }
 
      return _worksheets;
    } catch ( Exception ex ) {
      Trace.Write( ex.Message );
      throw;
    }
  }
 
 
  private DataSet LoadSpreadsheet( string filename, bool hasHeader ) {
    try {
      DataSet spreadsheet = new DataSet();
      string connectionString =
        @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source="
        + filename
        + ";Extended Properties=\"Excel 8.0;HDR="
        + ( hasHeader ? "Yes" : "No" )
        + ";IMEX=1\";";
 
      using ( OleDbConnection connection = new OleDbConnection( connectionString ) ) {
        connection.Open();
 
        using ( OleDbCommand command = new OleDbCommand() ) {
          using ( OleDbDataAdapter adapter = new OleDbDataAdapter( command ) ) {
            foreach ( string ws in this.GetWorksheets( connection ) ) {
              command.Connection = connection;
              command.CommandText = "select * from [" + ws + "]";
 
              DataTable table = new DataTable( ws );
              adapter.Fill( table );
 
              spreadsheet.Tables.Add( table );
            }
          }
        }
 
        connection.Close();
      }
 
      return spreadsheet;
    } catch ( Exception ex ) {
      Trace.Write( ex.Message );
      throw;
    }
  }
}

Dim blah As Excel.Application

Try
    Dim opn as New OpenFileDialog
    opn.InitialDirectory = "c:\wheremyfileis\myXLfiles"
opn.Filter = "Excel Files (*.xls)|*.xls"
opn.FilterIndex = 1
If opn.Showdirectory = Windows.Forms.DialogResult.Ok Then
   dim sb as system.text.stringbuilder = new system.text.stringbuilder("")
sb.append("Provider=Microsoft.Jet.OLEDB.4.0;")
sb.append("Data Source= ")
sb.append(opn.FileName)
sb.append(";Extended Properties = Excel 8.0;")
CNx = New system.data.oledb.oledbconnection(mycnn)
CNx.Open()
end if
DAx = New oledb.oledbdataadapter("select rcode, pcode, etc., "the exact column names found in your excel ", CNx)
DTx = New  DataTable
DAx.Fill(DTx)
Catch ex as exception
End try