Single page redirects with Apache and .htaccess not working

I don't know anything about Apache so please bear with me.
I'm trying to 301 redirect a single old page to a new one with the following line: However; that is not working. I have tested with two simple pages: old.html and new.html Which works fine. I friendly seo URLs enabled so I'm guessing it has something to do with this problem?
Can any of you guys help me out here please?

When you say "It doesn't work".....what actually happens?

Do you get an error? If so what is the error?

What is the URL produced by your redirect (if there is one)

I'm not a php programmer but redirecting a php script may be a lot more complex than redirecting a simple html page

It just goes to the old (missing) page.