Visual Studio 2005, C-language function - avoiding hacks?

I have PostgreSQL 8.4 installed on Windows XP, and am using Visual Studio
2005 to write a C-Language function. I have the most basic hello-world type
example (just the 'add_one' function from
http://www.postgresql.org/docs/8.4/interactive/xfunc-c.html) in a DLL, set
to compile to C code rather than C++, and I can do CREATE FUNCTION on it
then use it successfully. However, I had to do some questionable hacks to
get it to build, so I'm guessing I've done something the wrong way. I've not
found anything categorical in the archives here, so would very much
appreciate anyone who can tell me if there's a key step I'm missing that
would make the hacks unnecessary. (For instance, I've come across a
requirement in previous versions to replace pg_config.h with
pg_config.h.win32, but that doesn't seem to apply to current versions -
maybe something else does.) I'm concerned the hacks might turn round and
bite me otherwise once I'm implementing something non-trivial.

Having added C:\Program Files\PostgreSQL\8.4\include\server to the include
directories to pick up postgres.h and fmgr.h, the compiler complained about
various missing include files, starting with 'libintl.h'. Having read the
post at http://archives.postgresql.org/pgsql-general/2009-03/msg00332.php I
created an empty libint.h in an include dir, along with a bunch of other
empty dummy files that were expected: netdb.h, pwd.h, netinet/in.h and
arpa/inet.h.

The code then compiles ok, but gives 'inconsistent dll linkage' on the line
with PG_FUNCTION_INFO_V1 and the one with PG_MODULE_MAGIC.

So I'd like to ask:

* Is there some symbol I should be defining, or something, to avoid all
those dummy header files and make the corresponding Visual Studio headers
get picked up?

* Is there something I should be doing to avoid the 'inconsistent dll
linkage' warnings?

(The C-Language functions are going to end up using some in-proc
Windows-only components, so I'm hoping that building them using Visual
Studio will be the least painful way to get at those.)

Thanks in advance for any help

Kevin.