I'm a little stuck. I have the following redirect in .htaccess
Redirect http://www.domain1.com http://www.domain2.com/subdomain=
Although I want that if someone types www.domain1.com/12345, it will automatically append the 12345 to the redirect URL on redirect so it will go to www.domain2.com/subdomain=12345.
i.e. whatever they append to the original, will be appended to the new redirect (without a / before it).