Any way to bypass VPN selectively?

I've got a Buffalo WHR-HP-G54 running Victek's Tomato firmware Tomato-RAF-1.28.8525_VPN.

I've gotten the VPN working, but I'm wondering if there's any way to bypass the VPN selectively for certain machines, so some would connect through the VPN running on the router, and some would connect directly (bypassing the VPN).

Any ideas?