C#如何读取有自制表格和图片的excel？（如何越过表格和图片直接读取数据）

现在有一excel文件，里面有用户自制的表格以及图片，后面是正规的数据，我如何越过表格和图片，直接将后面的数据读取到dataset里？
下面是我的部分代码，请各位指点下？
 public void ReadExceldata()
        {
            try
            {
                string fileNameString = "";
                //申明打开对话框 
                OpenFileDialog dlg = new OpenFileDialog();
                //默然路径是系统当前路径 
                dlg.InitialDirectory = System.IO.Directory.GetCurrentDirectory();
                if (dlg.ShowDialog() == DialogResult.OK) 
                {
                    //返回文件路径 
                    fileNameString = dlg.FileName;
                    //验证strFileName是否为空或值无效 
                    if (fileNameString.Trim() == " ")
                    { return; }             string strCon = " Provider = Microsoft.Jet.OLEDB.4.0 ; Data Source =" + fileNameString + ";" + "Extended Properties=Excel 8.0;";
                    OleDbConnection myConn = new OleDbConnection(strCon);
                   // string strCom = " SELECT 厚度值,X坐标,Y坐标,厚度值1,X坐标1,Y坐标1,厚度值2,X坐标2,Y坐标2 FROM [原始$] ";
                    string strCom = " SELECT * FROM [原始$] ";
                    myConn.Open();
                    OleDbDataAdapter myCommand = new OleDbDataAdapter(strCom, myConn);
                    int i = 0;
                    myDataSet =new DataSet();
                    double tempt = 0;
                    
                    //double t=0;
                    
                    myCommand.Fill(myDataSet, 37, 450, "[原始$]");
                    //myCommand.Fill(myDataSet, "[原始$]");
                    for (i = 0; i < myDataSet.Tables[0].Rows.Count; i++)
                    {
                        for (int j = 0; j <= 6; j += 3)
                        {
                            tempt = (double)myDataSet.Tables[0].Rows[i][j];
                            t = t + tempt;
                        }                    }
                    avgt = t / (3 * (i+1));                    MessageBox.Show(avgt.ToString().Substring(0, 4));
                    myConn.Close();
                    //**********************************************
                }
                
            }
            catch (Exception emm)
            {
               // MessageBox.Show(emm.ToString());
                MessageBox.Show("请选择正确格式的壁厚数据");
            }
            finally
            {
                
            }
        }