Apache mod rewrite masking

Question

I'm trying to mask/hide a the URL of our VPS, in which we have installed a wordpress blog under a subdirectory (/var/www/vhosts/vps.url.com/httdocs/blog.

We have a domain pointing to this site (vps.url/blog), so writing the domain URL on the browser redirect us to the VPS, but showing the URL vps.url/blog.

I've tried to mask it with apache2 virtual hosts this way:

    <VirtualHost *:7080>
        ServerAdmin webmaster@localhost

        ServerName domain.es
        ServerAlias www.domain.es
        DocumentRoot /var/www/vhosts/vps.url.com/httpdocs/domain/

        DocumentRoot /var/www
        <Directory />
                Options FollowSymLinks
                AllowOverride None
        </Directory>
        <Directory /var/www/>
                Options Indexes FollowSymLinks MultiViews
                AllowOverride None
                Order allow,deny
                allow from all
        </Directory>

        ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/
        <Directory "/usr/lib/cgi-bin">
                AllowOverride None
                Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch
                Order allow,deny
                Allow from all
        </Directory>

        ErrorLog ${APACHE_LOG_DIR}/error.log

        # Possible values include: debug, info, notice, warn, error, crit,
        # alert, emerg.
        LogLevel warn

        CustomLog ${APACHE_LOG_DIR}/access.log combined

    Alias /doc/ "/usr/share/doc/"
    <Directory "/usr/share/doc/">
        Options Indexes MultiViews FollowSymLinks
        AllowOverride None
        Order deny,allow
        Deny from all
        Allow from 127.0.0.0/255.0.0.0 ::1/128
    </Directory>
</VirtualHost>

This doesn't work as it still showing vps.url.com/domain when we want to show domain.es

Thanks before hand and excuse my bad english.