Question : rewrite rule

we have a rewrite rule:

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^([-a-zA-Z-0-9]+)/([-a-zA-Z-0-9]+)/([-a-zA-Z-0-9]+).([-a-zA-Z-0-9]+)$ showfinal.php?brand=$1&app=$2&m=$3&s=$4 [L]

having this rule in mind how would we make a rule for something like
Gibson/Cook-Top/sitemap.xml  
to go to /sitemap.xml

basically we want a rule where no matter what is in the query string if we have sitemap.xml at the end it'll go to /sitemap.xml

Answer : rewrite rule

ok this issue was resolved in my other posted questions at
http://www.experts-exchange.com/Software/Server_Software/Web_Servers/Apache/Q_26288513.html#a33081856