It's trying to run the M$ compiler from VC++ (which is named cl and is what AS builds with). I'm not a Wintendo person (and much happier for it), but I'm pretty sure you don't want to try to use a different compiler to build extensions from what was used to build perl. Of course that could be outdated information.

As was recommended previously, it's much easier to use ppm in Wintendo land and install a precompiled version someone else has already gotten working.