I don't know specifically about RJs, but in general the same control inputs (aileron & rudder) you need to maintain track just before rotation are a good start for rotation and liftoff. After you're airborne, level the wings and let go any rudder input to start your initial outbound track. The initial aileron and rudder inputs will likely set you up on a reasonable track with some crosswind correction. Fine tune it after the wheels are coming up.