Finding text between tags and replacing it along with the tags

Question

I am using The following regex pattern to find text between [code] and [/code] tags:

(?<=[code]).*?(?=[/code])

Answer 1

I would use a HTML Parser for this. I can see that what you are trying to do is simple, however these things have a habit to get much more complicated overtime. The end result is much pain for the poor sole who has to maintain the code in the future.

Take a look at this question about HTML Parsers
What is the best way to parse html in C#?

[Edit]
Here is a much more relevant answer to the question asked. @Milad Naseri regex is correct you just need to do something like

string matchCodeTag = @"\[code\](.*?)\[/code\]";
string textToReplace = "[code]The Ape Men are comming[/code]";
string replaceWith = "Keep Calm";
string output = Regex.Replace(textToReplace, matchCodeTag, replaceWith);

Check out this web sites for more examples
http://www.dotnetperls.com/regex-replace
http://oreilly.com/windows/archive/csharp-regular-expressions.html

Hope this helps