Can only victor way be used for route in cross country?
You just use (starting waypoint)  DCT  (ending waypoint) in your flight plan (DCT = Direct) and submit that.  It's up to ATC to approve that routing and you'll find out when you are issued your clearance.  

Especially at lower altitudes it's likely you'll be cleared as filed, but there's always a chance they'll shift your route a bit to improve traffic flow for whatever reason, adding waypoints or moving you to an adjacent V airway, doing their best to minimize any increase in your distance.