A very simple mechanism for reading old URLs and doing 301 redirects to new URLs, based on a spreadsheet.

<%@ Language = JScript%>
<% 
  var originalUrl = Request.ServerVariables("HTTP_X_ORIGINAL_URL");
  var newUrl = null; 
  var root = Request.ServerVariables("APPL_PHYSICAL_PATH");
  var connStr = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=";
  connStr += String(root);
  connStr += ';Extended Properties="text;HDR=Yes;FMT-Delimited";';
  
  var conn = Server.CreateObject("ADODB.Connection");
  conn.open(connStr);

  var rs = Server.CreateObject("ADODB.recordset");
  rs.open("SELECT * FROM links.csv", conn);
  
  while (!rs.EOF) {
    if ( String(rs("OLDURL")) == String(originalUrl) ) {
      newUrl = String( rs("NEWURL") );
      break;
    }
    rs.moveNext();
  }
  rs.close();
  if (newUrl != null) {
    Response.Status = "301 Moved Permanently";
    Response.AddHeader("Location", newUrl);
  }
%>