linux - 301 Redirect issue when term in new and old URL

We are trying to create a set of 301 redirects where the exact string from the old URL is also present in the same position in the new URL. See the example below:

Old URL

http://www.domain.com/foobar

New URL

http://www.domain.com/foobar/i55

We've tried a standard 301 redirect like this:

Redirect 301 /foobar$ http://www.domain.com/foobar/i55

This doesn't work and causes a 404:

File does not exist: /home/domain/public_html/foobar

Should we be looking at rewrite rules instead or can this be fixed by just adjusting the 301 rule?

Thanks.

Answer

You need to use the RedirectMatch in mod_alias i.e:

RedirectMatch 301 /foobar$ http://www.domain.com/foobar/i55

EDITED BASED COMMENT