What is the laptop running? Linux? Windows? OS/X? If it's Linux, you can try this approach.
I tunnel all the traffic between a workstation and my Linux external router to add an additional layer of security to the wifi connection it uses and to facilitate a couple of services that need to see the workstation directly.
It's a bit tricky to set up because you have to make sure you have a route to the VPN server so you can pass the traffic between them, but use the tunnel for everything else.
For reference, I'll post the script I use. I run this after I've set up the connection to my wifi router at 192.168.1.1:
When finished, my routing table looks like this:
# check to see if I have connected to the router
TEST=`ifconfig | grep 'inet addr:192.168.1'`
if [ "$TEST" != "" ]
# add a route to the VPN router at 192.168.100.1 using the wifi connection
ip route add 192.168.100.1 via 192.168.1.1
# restart VPN to connect to the router and create the tunnel
# repoint my default route to use the remote tunnel IP (10.100.1.1)
ip route del default
ip route add default via 10.100.1.1
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.100.1 192.168.1.1 255.255.255.255 UGH 0 0 0 wlan0
10.100.1.1 0.0.0.0 255.255.255.255 UH 0 0 0 tun0
192.168.1.0 0.0.0.0 255.255.255.0 U 2 0 0 wlan0
0.0.0.0 10.100.1.1 0.0.0.0 UG 0 0 0 tun0