  Using data collected with the BESIII detector operating at the Beijing
Electron Positron Collider at center-of-mass energies of $\sqrt{s}=4.23$, 4.26,
and 4.36~GeV, we observe $\EE\to \pphc$ for the first time. The Born cross
sections are measured and found to be about half of those of $\EE\to
\pi^+\pi^-h_c$ within less than 2$\sigma$. In the $\pi^0h_c$ mass spectrum, a
structure at 4.02~GeV/$c^2$ is found. It is most likely to be the neutral
isospin partner of the $\zcp^{\pm}$ observed in the process of $\EE\to
\pi^+\pi^-h_c$ is found. A fit to the $\pi^0 h_c$ invariant mass spectrum, with
the width of the $\zcpn$ fixed to that of its charged isospin partner and
possible interferences with non-$\zcpn$ amplitudes neglected, gives a mass of
($4023.9\pm 2.2 \pm 3.8$)~MeV/$c^2$ for the $\zcpn$, where the first error is
statistical and the second systematic.
