  We discuss the relevance of a dedicated measurement of exclusive production
of a pair of neutral pions in a hard gamma* gamma scattering at small momentum
transfer. In this case, the virtuality of one photon provides us with a hard
scale in the process, enabling us to perform a QCD calculation of this reaction
rate using the concept of Transition Distribution Amplitudes (TDA). Those are
related by sum rules to the pion axial form factor F^pi_A and, as a direct
consequence, a cross-section measurement of this process at intense beam
electron-positron colliders such as CLEO, KEK-B and PEP-II, or Super-B would
provide us with a unique measurement of the neutral pion axial form factor
F^pi0_A at small scale.
