Can a Cisco 831 establish a VPN tunnel via a Cisco 2620?

We have a situation where we want to be able to use VoIP phones in a remote
office and have them able to connect to our 3Com NBX. We were told by 3Com
that if we added a router in the remote office (we have DSL) and established
a VPN tunnel to our network, then phones (also 3Com) could work with our NBX
and act as though they were in the local network.

We already have a 2620 router configured between our network and the
internet. We can connect to the network on workstations by using a DUN
object that our consultants created that connects through the router and
verifies access via AD.

We bought a Cisco 831 because it was supposed to have VPN as well as support
Ethernet broadband. We're having trouble getting EasyVPN set up. The router
is functioning and is connected to the internet. However, we're stuck in the
EasyVPN setup that wants a "Group ID" and password.

Any ideas? Has anyone done something like this? Can we do this with an 831
and 2620??