301 On Url With Features

Hi,

I wanted to make a 301 for several of my indexed by Google, ranked, URLs with features.

The src URL is:

www.example.com/mac/macbook-pro.html?subcats=Y&features_hash=V231

The target URL is:

www.example.com/mac/macbook-pro.html?features_hash=18-231

I tried putting in htaccess:

RewriteEngine On
RewriteCond %{QUERY_STRING} ^subcats=Y&features_hash=V(231)$
RewriteRule /mac/macbook-pro.html /mac/macbook-pro.html?features_hash=18-%1 [R=301,L]

But it does not work, although I think it should.

It is impossible using the SEO plugin in backend, right?