This two-part article is aimed at experienced C# .NET programmers who wish to write their own little computer languages (see http://www.codeproject.com/KB/recipes/YourFirstDSLPart2.aspx here). Historically, this has been reasonably difficult due to requiring in-depth knowledge of compilation theory and/or the use of one or more tools, each of which had its own learning curves. Recently though, there has been somewhat of a revolution in this area, with tools being developed which greatly simplify the writing of compilers. http://www.codeplex.com/irony/ for .NET is used in this tutorial due to the fact that it requires no configuration files etc. (Just drop the Irony DLL into your project) and it simplifies many aspects of compiler construction.
Refer : http://www.codeproject.com/KB/recipes/YourFirstDSL.aspx