proxy subdirectory not being kept after redirection (Apache Users)

Hello everyone,

I have an issue with the proxy and subdirectory on httpd. What I wanted is whenever clients access http://mydomain.com/host1/, the server host A will proxy it to host B internally, with the URI http://mydomain.com/host1/ base unchanged. The httpd.conf on host A has the following:

<VirtualHost *:80>
ServerName mydomain.com
ProxyPreserveHost on
<Location “/host1/“>
ProxyPass "http://192.168.4.12/" retry=0
ProxyPassReverse "http://192.168.4.12/"
</Location>
</VirtualHost>

In the above httpd.conf, the internal IP 192.168.4.12 is the IP of the host B, and host1 is just a virtual directory that I’d like to name it. The host B is serving phpMyAdmin page, with the following httpd.conf

<VirtualHost *:80>
DocumentRoot /var/www/html/phpMyAdmin
<Directory /var/www/html/phpMyAdmin>
Options Indexes FollowSymLinks MultiViews
AllowOverride All
Order allow,deny
allow from all
</Directory>
ServerName 192.168.4.12
ErrorLog logs/192.168.4.12_81_error_log
CustomLog logs/192.168.4.12_81_access_log common
</VirtualHost>

Accessing phpMyAdmin on host B internally in my network, with the URL http://192.168.4.12/ work just fine, ie http://192.168.4.12/index.php?abc will show http://192.168.4.12/index.php?abc. However, when I tried externally, it does not work as expected:

Accessing http://mydomain.com/host1/index.php works fine, showing phpMyAdmin log in page
After entering username / password to log in, the URL on my browser becomes http://mydomain.com/index.php?token=abc instead of http://mydomain.com/host1/index.php?token=abc. Somehow the virtual subdirectory host1 disappeared.

Please help!

Thanks