ReplaceTags

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;


class ReplaceTags
{
    static void Main()
    {
        string text = @"<p>Please visit <a href=""http://academy.telerik.com"">our site</a> to choose a training course. Also visit <a href=""www.devbg.org"">our forum</a> to discuss the courses.</p>";

        string replaced = text.Replace(@"<a href=""", "[URL=");
        replaced = replaced.Replace(@"</a>", "[/URL]");
        replaced = replaced.Replace(@""">", "]");
        Console.WriteLine(replaced);
    }
}