How can I make the Makefile pass options to autoconf when configure.ac is updated?

[Stephano Mariani]

I need to pass a --m4dir to autoconf to generate the configure script
correctly, how can I do this so that whenever configure regenerated by
the automake rule:

cd . && /bin/sh /path/to/project/missing --run aclocal
cd . && \
  /bin/sh /path/to/project/missing --run automake --foreign  Makefile
cd . && /bin/sh //path/to/project/missing --run autoconf

(In `missing` perhaps?) It passes this option?

TIA,
Stephano Mariani

PS: I did not know which list this applied to so sorry for the
cross-post.