Compiling php_*.dll extensions on Win32

Hi I am trying to compile the OCI8 extension for Win32. I already tried a few things: Making an empty .dll project and adding oci8.c and php_oci8.h and compiling. This compiles fine but PHP4 does not recognize it as a valid PHP extension. I looked at the modules workspace (with pgsql, mysql, imap) and copying the mysql and replacing the mysql stuff with the Oci8 files. This had the same result as the procedure described above. Could somebody give me some hints on how to compile extensions under Win32 in general. Why are the extensions not distibuted in compiled form in the Betas? When I get it working I will try to write a short doc. Thanks, Florian