How to go from one row to another row in datarow?

Question

I am new in C#..struggling to learn it..Can anyone help me in this..i want to know how can i go from one row to other row based on previous row value..

Example:1st row-> MerchantNo:001102534
  2nd row->OutletName
  3rd row->Emptyrow
  4th row ->MerchantNo  TerminalNum  CardType  ....
  5th row ->1102534  7700100456  Amex
 I am having a datatable filled with this kind of data..I have written a code for removing the characters from 1st row and to give only the number.Now based on this number  i want to go to all those rows which contains this number and want to retrieve the data from that row and insert it into sql table..
how can i do this...hope u understood my doubt..This is the code which i have written..
  string Mno = "";
  foreach (DataRow rowExcel in dtExcel.Rows)
  {

  foreach (DataColumn colExcel in dtExcel.Columns)
  {
  Mno = rowExcel[colExcel].ToString().Trim();
  if (Mno != "")
  {
  string Mno1 = Mno.Substring(16, 10);
  Mno =Mno1.ToString();
  //Int32 MerchNo = Convert.ToInt32(Mno);
  }
  break;
  }
  if(Mno!="")
  break;

  }
How can i proceed further..