.htaccess重定向所有文件但有例外

I know this has been asked thousands times, but I've been googling for three hours without any result. So I'm asking here. I'm creating a website. All the content is in the folder /subfolder. Now I want to redirect all the requests to another domain (let's say domain.com), at the exception of the files that I actually use. It may seem weird but it makes sense in my situation. So what I have at the moment is I know this has been asked thousands times, but