In this case you can use Qvpn (IPsec client) from your windows 7 to connect to the destination local (p.q.b.0)
For the configuration of Qvpn on RV042 you need just to create the VPN users and enable the remote management
on port 443
But in your topology the RV042 is behind a NAT so you need to configure the ADSL router to forward the following port : 500 UDP , 4500 UDP and 443 TCP to WAN interface of RV042 (p.q.a.2)