Parsing large flat files with irregular delimiters

using System;
using System.Collections;
using System.IO;
using System.Text;
using System.Text.RegularExpressions;

namespace FileSplitter
{
   class Program
   {
      public static void Main(string[] args)
      {
         if(args.Length < 4){
            Console.WriteLine("Usage: <path> <column delim> <row delim> <max rows>");
            
         }
         else
         {
            string FilePathnName    = args[0];
            string oFilePathnName   = "Candidates";
            //string oFilePathnName = "Requisitions";
            string cLine         = null;
            string cDelim          = null;
            string rDelim          = "<><>";
            string nRow            = null;
            string oRow            = null;
            string sRow          = null;
            int iCount         = 0;
            string strBuild         = null;
            string sColumn      = "candidatehrms_code|firstname|middlename|lastname|address1|address2|city|state|zip|countryhrms_code|email|login|password|isemployee|statushrms_code|resumertf|referraltypehrms_code|referraldetail|active|homephone<><>";
            //string sColumn       = "requisitionhrms_code|jobtitle|markettitle|orderdate|statusdate|createdate|internalexpires|jobcode|jobgradehrms_code|externaljobdescription|internaljobdescription|approved|statushrms_code|openings|placements|flsaexempt|fullpart|eligibleemployeereferral|wagecurrencyhrms_code|countryhrms_code|departmentshrms_code|locationhrms_code|hiringmanagerhrms_code|recruiterhrms_code|eeocodehrms_code|jobcategoryhrms_code|percenttravel|workflowhrms_code|webapproved|confidentialreq|supervisory|active|udfhirereqid|requisitiontypehrms_code|employmenttypehrms_code|incumbentname|aibtarget<><>";
            
            
            
            StreamReader sReader = new StreamReader(FilePathnName);
            StreamWriter sWriter;
            
            
            while(sReader.Peek() >= 0){
               sRow = sRow + sReader.ReadLine();
               if(sRow.Contains("~~")){
                     iCount = iCount + 1 ;
                      string[]    dRow = sRow.Split("~~".ToCharArray());
                     if(dRow.Length > 1){
                         
                         oRow = dRow[0];
                         sRow = dRow[1] + dRow[2];
                         strBuild = strBuild + oRow + "<><>";
                         if(iCount == 1500){
                            strBuild = sColumn + strBuild;
                            sWriter = File.CreateText(oFilePathnName + "_" + DateTime.Now.ToString("yyyyMMdd")+ "_" + DateTime.Now.ToString("HHmmss")+ ".txt");
                            sWriter.Write(strBuild);
                           sWriter.Close();
                           iCount = 0;
                           strBuild = null;
                         }
                         else{
                            if(sReader.Peek() <= 0 ){
                               strBuild = sColumn + strBuild;
                               sWriter = File.CreateText(oFilePathnName + "_" + DateTime.Now.ToString("yyyyMMdd")+ "_" + DateTime.Now.ToString("HHmmss")+ ".txt");
                              sWriter.Write(strBuild);
                              sWriter.Close();
                              iCount = 0;
                              strBuild = null;
                         }
                      }
                  }
               }
            }
         }      
      }
   }
}