  We describe a controllable and precise laser tweezers for Bose-Einstein
condensates of ultracold atomic gases. In our configuration, a laser beam is
used to locally modify the sign of the scattering length in the vicinity of a
trapped BEC. The induced attractive interactions between atoms allow to extract
and transport a controllable number of atoms. We analyze, through numerical
simulations, the number of emitted atoms as a function of the width and
intensity of the outcoupling beam. We also study different configurations of
our system, as the use of moving beams. The main advantage of using the control
laser beam to modify the nonlinear interactions in comparison to the usual way
of inducing optical forces, i.e. through linear trapping potentials, is to
improve the controllability of the outcoupled solitary wave-packet, which opens
new possibilities for engineering macroscopic quantum states.
