Unless I am greatly mistaken, XS requires that you use the compiler used to compile your Perl. Thus, you have no choice. perl -V (note the capital 'V') will give you more information about the compiler used and the options used with it. With Activestate, this should be cl.exe, which restricts you to the MS C++ compiler.

Cheers,
Ovid

New address of my CGI Course.
Silence is Evil (feel free to copy and distribute widely - note copyright text)