We study dynamics of discrete vortex strings interacting in a background vorticity distribution by using a magnetized electron plasma confined by a potential distribution in a cylindrical trap, and demonstrate relevant 2-dimensional features characterizing the incompressible dissipation-free guiding-center fluid. Some specific elementary processes are examined and compared with a recently proposed theoretical model that describes a motion of a point vortex moving up a hill of background vorticity distribution. Radial transport of particles is observed to be very limited and associated with several conserved parameters.