If you change the PIX 515 to a router or VPN 3000 concentrator, the answer is yes. Because the router and VPN 3000 concentrator can redirect ip traffic from same interface.
PIX, for security reason, the same interface will not redirect traffic. So whatever you do, you will not be able to redirect the VPN client traffic to another VPN tunnel to another remote office.
That is the way it is for PIX.