To create the code for different languages choice, for a website already created with "RapidWeaver"

I need to create the possibility for my clients to go to the website [login to view URL] and choose their language. At the moment, In most of this website menus, all 4 languages are mixed and the menus names are only in 1 language. We need the typical country flags that represent the languages (Portuguese, English, Spanish and French), so that the client can choose his language and then navigate trough all the website in his language. So, I need: - the country flag creation (HTML for Rapidheaver?) - the "quaduplication" to put all the data in each language (mirrors?) The problem is that if the code is not embed in Rapidweaver, then my client cannot continue to refresh he website, because he only knows how to work with Rapidweaver. I'm opened to new/different solutions. Thank you! PCGM