Port ndbm to newlib

Hello everyone,
I am trying to port  ndbm.h  from freebsd to newlib.

   - i have placed  ndbm.c  file in    newlib/libc/posix   directory.
   - this .c file requires    hash.h    which is inside     libc/search
   directory
   - The default source for header files , for .c files in posix is
   libc/include.

I want to add libc/search as an alternative path for ndbm.c for header
files.
I did checked    libc/posix/Makefile.am    and    libc/configure.in   to do
so, but not getting any hint about it.

Please help me out with this.

Thank You
Vaibhav Gupta