How to Convert BB Code To HTML view (VB.NET)

The point of my idea is to write a program for a Web site that has it's own BB CODE (开发者_开发知识库PHP) ,then user of the program can write his message and range his message with this BB code (inside the program) , all this can be done easily , but just one thing I can't do , How can I add a Review before send with this BB code (without connect to internet) , I mean convert this bb code to a HTML page has the same appearence of the eal message .

Not sure I've fully understood your question. You want a preview without sending the form to the server? Try replacing the BB codes with javascript (using regular expressions might be a hint).