newbie : For windows-target of PDO-driverr, CrossCompile or native-compile?

Hello,
I need to write PHP-PDO database-driver for a new database.

The clarification I need:
1) Should I take the PHP-source on Windows-vista platform and build natively
the DLL for win.
   Will the VisualStudio compile with all PHP-main src & the extension
driver to generate the  target windows DLL (PDO extension).

or

2) should I take PHP-src on Linux platform and use GNU Cross-compiler to
generate DLL. Then transfer the DLL to the target windows PHP env.