[Proj] Create a new customize projection

[francescoboccacci at libero.it]

Hi to all,
i have a question for you. I'd like to create a new projection that is a 
acustomization of a mercator projection. I'd like to create a new projection 
like this "+proj=newmerc" where i set some new parameter and formulas. Can i do 
that? What i need to modify? i try to copy and paste  PJ_merc.c with a new name 
PJ_newmerc.c and insede the code i change like that:

#define PJ_LIB__
#include        <projects.h>
PROJ_HEAD(newmerc, "NewMercator") "\n\tCyl, Sph&Ell\n\tlat_ts=";
..
i recompile all with make and make install.
I try to run proj -l but i can see newmerc.

can anybody help me?

Thanks


Francesco