  In order to describe few-body scattering in the case of the Coulomb
interaction, an approach based on splitting the reaction potential into a
finite range part and a long range tail part is presented. The solution to the
Schr\"odinger equation for the long range tail is used as an incoming wave in
an inhomogeneous Schr\"odinger equation with the finite range potential. The
resulting equation with asymptotic outgoing waves is then solved with the
exterior complex scaling. The potential splitting approach is illustrated with
calculations of scattering processes in the H${}^+$ -- H${}^+_2$ system
considered as the three-body system with one-state electronic potential
surface.
