Cisco 877W VPN

I want to create a VPN such that any of my remote workers can use the Cisco VPN client and connect to my network.

I am running 2 subnets which both acess the net via the same Cisco 877W router (with SDM). 1 subnet is a home network (192.168.1.0) which is the network my router is sat on. The other subnet is my office network (192.168.0.0) which has a 2K3 domain control, linux based radius server/gateway and linux based mail server which both have two NICs so they can sit in both networks.

All home internet traffic goes straight to the router while office traffic goes via the radius/gateway server to the router.

My 2K3 domain controller issues DHCP leases for clients on the internal network and a separate DHCP server siste on the home network for clients at home.

I would like to be able to let users, authenticated by the radius server, connect to the 192.168.0.0 network using the VPN client while they are away or working from home.

The following details may be relevant/helpful..

model: Cisco 877W with SDM
sdm version: 2.3
IOS version: 12.4(4)T4

Using ADSL (DSL/PPPoA)

Any help in setting this up would be greatly appreciated