Isomerization of HCN is studied numerically for a laser excitation configuration of two perpendicular intense IR pulses, This scheme confines the molecule to a plane and promotes proton transfer along the curved reaction path. It is shown that internal rotation of the CN group enhances isomerization when compared to a fixed C=N orientation model. Isomerization rates with rotation exceed those without rotation of the CN by about a factor of 3. Internal rotation also enhances. dissociation and destroys phase control of the isomerization. It is found that at intensities I similar to 10(13) W/cm(2), maximum isomerization occurs with negligible dissociation for a 2 ps pulse excitation. Maximum isomerization is also found for one field frequency resonant with the CH bend frequency omega(bend) and the other perpendicular frequency at 2 omega(bend).