Redirect Help to a subdomain

We are moving our news articles from our main web site to a new blog sub domain. I’m trying to get the redirection to work in HAProxy, but having some issues. I’m running 1.5 on a CentOS 7 server. What I’m wanting to do is change

Here’s what I’ve got so far.

acl newspage url_beg /news/post/
http-request redirect code 301 location[capture.req.uri] if newspage

But I need to strip out the /news/post part of the uri. That’s where I’m stuck.
I’ve tried
but that just puts me at the root, it doesn’t preserve the specific page.