I figured out how to redirect someone, if they happen across one particular filename:

Redirect /index.php http://www.website.com/#myaccount

As you can see, I'm pretty much redirecting that visitor to the same page, which doesn't work. It's an endless look, regardless of the slight/minuscule change.

I want to force someone to see a part of the page, by adding the hash. (it's a little weird, I know)

I'm guessing this may be a time to use regex in the htaccess file.
But I thought I'd ask if there's a simpler way to do this from the htaccess file.