Linux VirtualBox guest as proxy for host

[Jitsu]

Could not find answer on forums/google.

Want to create a sandbox server to play with.
Now I have following network config:
myPC -> Ubuntu Local Server -> Internet
I want to have:
myPC_Host -> Ubuntu_guest(as server and proxy) -> myPC_host -> Ubuntu Local Server -> Internet
so I'll be able to play with different settings for squid/firewall/etc on Ubuntu_guest and test internet accessability on myPC_Host.
Is it possible with virtualbox?

Thanks.

[vbox4me2]

Create a VM using 1 bridge and 1 internal network connection, hook the sandbox VM to the internal LAN, use primairy VM as a router/firewall.