Redirect all requests to subdirectory except a few ip addresses

Question

This question attempts to combine knowledge gained from some previous answers on SO, so do not mark as a duplicate unless the answer is meets the all of criteria about to be

Answer 1

How about:

RewriteEngine On

# for #2
RewriteCond %{REMOTE_ADDR} !123\.45\.67\.89$
RewriteCond %{REMOTE_ADDR} !123\.45\.67\.90$

# for #1 and #3 and #4
RewriteCond %{REQUEST_URI} !^/website/ [NC]
RewriteRule ^(.*)$ http://www.example.com/website/$1 [R=302,L]

For #2 you want to replace the 123\.45\.67\.89 etc with the IP addresses that you want not to be redirected.

For #4, the R=301 needed to be changed to R=302