Split Tunnel with PPTP VPN

Hello. How do I enable split tunneling in Vista's PPTP VPN client????

In Windows XP, when I connect to my VPN gateway at work, I run a batch
command script to establish routes to all subnets at work and remove the
default gateway on the VPN connection's IP address. This way, only the
subnets going to my workplace will be routed through the tunnel and all of
my Internet access will go through my normal connection through my DSL.

In Vista, I can't do this anymore! It insists on sending all packets
through the vpn tunnel!

What am I missing?

Thanks in advance.