How to remotely connect a pc in lan

Hi,

I want to connect my school pc from home. The pc at school is running 24hours in the lan connected via a proxy server and has access to internet.

The Pc in lan has a IP which is probably the IP of proxy server. Because whenever I tried to reveal the IP from different computers it shows the same IP at the same time.

Is there any way to access that pc.

Regards,