Can someone please advise me on how I can ping an IP address sitting behind a Netgear DG843 from another site?

I take it I will need to setup a VPN but am unsure on how to approach this, please help

Current setup:-
Site 1:
Netgear Router DS843 Static IP : 81.130.211.x
Netgear Router LAN: 192.168.0.1
PC (I want to ping): 192.168.0.50

Site 2:
Cisco Router 1841 Static IP: 217.46.156.x
Cisco Router 1841 LAN: 192.168.1.1 (can ping 81.130.211.x but not 192.168.0.50)