  The $D^*D\pi$ form factor is evaluated at low and moderate $Q^2$ in a
hadronic loop model, for off-shell $D$ mesons. The results contain arbitrary
constants, which are fixed so as to match previous QCD sum rule calculations
valid at higher $Q^2$. The form factor obtained in this way was used to extract
the coupling constant, which is in very good agreement with the experimental
value.
