Proxy

I have to use a proxy to grab from a site that is geo blocked, can I add the proxy in a large config file towards the end?

For example:

<channel update="" site="yourtv.com.au" site_id="MOVIE EXTRA" xmltv_id="MOVIE EXTRA">MOVIE EXTRA</channel>
<channel update="" site="tv-guide.upc.at" site_id="gy" xmltv_id="ORF eins">ORF eins</channel>

<proxy user="username" password="password">192.168.2.4:8080</proxy>

<channel update="" site="blocked-site.com" site_id="1" xmltv_id="1">One</channel>
<channel update="" site="blocked-site.com" site_id="2" xmltv_id="2">Two</channel>

Also, how can I close the proxy to continue to grab from other sites not requiring a proxy or change to a different proxy after this?

Thanks.