Force a program to bind to a network card

http://www.r1ch.net/stuff/forcebindip/

ForceBindIP is a freeware Windows application that will inject itself
into another application and alter how certain Windows Sockets calls
are made, allowing you to force the other application to use a
specific network interface / IP address. This is useful if you are in
an environment with multiple interfaces and your application has no
such option for binding to a specific interface.