Im trying to figure out how to get a network going from 4 Antrouter R1's through a connection that needs a vpn...

i will try and make a text diagram below


Antrouter--\           
Antrouter--\         
Antrouter------- switch box -------   Dual Ethernet Mobo --------Connection Requiring VPN
Antrouter--/                            (eth 0)                     (eth1)


the connection on ethernet port 1 needs a VPN..
will be connecting the Antrouters to the switch then to Ethernet 0 connecting at a Getwork Proxy then through the VPN on Ethernet 1

Trouble is i cant rap my head around getting the VPN on Ethernet 1 and allowing connections via Ethernet 0 from the Switch Proxy

Anyone with A network background could help a poor guy out?.