In the project workspace, select pcre as the active project
There is a define missing, so in projects/options add the define: HAVE_PCRE=1

In the file php3_pcre.h some lines are missing, so add them after line 58:

#include "dl/phpdl.h"
#if COMPILE_DL
DLEXPORT php3_module_entry *get_module(void) { return &pcre_module_entry; }
#endif

Here we are ! You get php3_pcre.dll working under Win32 !
There are also 2 other warnings that must be treated in php.exe, but I'll create another bug report for that.