dual wan problem

[jimmer]

have rt-n66 router running current merlin firmware
setup dual wan to route internet traffic to fios isp and TWCTV apps to a TWC ubee video only modem.
need the daul wan to route to a range of desination ip addresses 71.64.0.0 - 71.79.255.255 where the individual channels reside for the TWCTV apps
I can only see how to set each individual ip route-
Any easy way to achieve this?

 

[jimmer]

Since many have looked but no one has commented I'll try to clarify a little. My isp is verizon Fios and Cable TV is TWC. TWC's internet speeds and service are awful here. To watch the TWC channels on tablets and roku's they provide a modem/router that when connected to it with wifi routes all TWCTV.com requests to the ip addresses above (appears that each channel has a separate address when tuned). It's a real pain to keep switching the wifi back and forth on all the gadgets and would be nice to have one wifi through the RT-N66w that would then route to the bridged fios modem/ router for everything except requests to twctv.com or the ip range above (whichever is easier) to the TWC modem/router.
when I purchased the router I thought that it would allow an ip range for the dual wan routing not each single ip address.Looking for a way to achieve this. Seems like there should be a way to do so. Any suggestions would be much appreciated.