  The knowledge of the nuclear matrix elements for the neutrinoless double beta
decay is fundamental for neutrino physics. In this paper, an innovative
technique to extract information on the nuclear matrix elements by measuring
the cross section of a double charge exchange nuclear reaction is proposed. The
basic point is that the initial and final state wave functions in the two
processes are the same and the transition operators are similar. The double
charge exchange cross sections can be factorized in a nuclear structure term
containing the matrix elements and a nuclear reaction factor. First pioneering
experimental results for the 40Ca(18O,18Ne)40Ar reaction at 270 MeV incident
energy show that such cross section factorization reasonably holds for the
crucial 0+ --> 0+ transition to 40Args, at least at very forward angles.
