Problem Linking to a CPP Extension using VC6

I'm going to be developing a C++ php extension that needs to run under 
windows.  It needs to work with VC6 so it can work with the stock apache 
binaries.  So far, following the steps on 
http://wiki.php.net/internals/windows/stepbystepbuild, I've been able to 
compile php with the default extensions and have successfully compiled 
various extensions from pecl. 

I've created a basic hello world extension that compiles (and works) 
without problems when it is a .c file.  But if I make it a .cpp file I 
can no longer compile it because I get a linker error.  The error I'm 
getting is:

internal_functions.obj : error LNK2001: unresolved external symbol 
_sample_module_entry
Release_TS\php5ts.dll : fatal error LNK1120: 1 unresolved externals
NMAKE : fatal error U1077: '"C:\Program Files\Microsoft Visual 
Studio\VC98\bin\cl.exe"' : return code '0x2'

What do I need to do to compile a c++ extension correctly?  Is there 
something I'm missing in my config.w32 file?  I know the config.m4 file 
needs REQUIRE_CXX(), is there an equivalent in the config.w32?

Since the source is really small for my test extension I'm including it 
at the end of this message.  Please let me know what I'm doing wrong or 
if what I'm doing is possible. I understand that for my test extension 
that I don't need c++ but for what I want to write I will need c++.  Any 
help will be appreciated.

Thanks,
~Jeff Whiting


config.w32:

ARG_ENABLE("sample", "whether to enable the sample extension", "no");

if (PHP_SAMPLE != "no")
{
  EXTENSION("sample", "php_sample.cpp");
}


php_sample.h:

#ifndef PHP_SAMPLE_H
#define PHP_SAMPLE_H

#define PHP_SAMPLE_EXTNAME "sample"
#define PHP_SAMPLE_EXTVER "1.0"

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "php.h"

extern zend_module_entry sample_module_entry;
#define phpext_sample_ptr &sample_module_entry

#endif


php_sample.cpp:

#include "php_sample.h"

PHP_FUNCTION(sample_hello_world)
{
    php_printf("Hello World!\n");
}

static function_entry sample_protocol_functions[] = {
  PHP_FE(sample_hello_world, NULL)
  {NULL, NULL, NULL}
};

zend_module_entry sample_module_entry = {
  STANDARD_MODULE_HEADER,
  PHP_SAMPLE_EXTNAME,
  sample_protocol_functions, //FUNC
  NULL, //MINIT
  NULL, //MSHUT
  NULL, //RINIT
  NULL, //RSHUTDOWN
  NULL, //MINFO
  PHP_SAMPLE_EXTVER,
  STANDARD_MODULE_PROPERTIES
};

#ifdef COMPILE_DL_SAMPLE
ZEND_GET_MODULE(sample)
#endif