How to compile Qt for 64-bit Windows from a 32-bit environment with Visual C++ 2010 Express?

I am trying to compile the Qt library (I don't need the demos or examples) for 64-bit Windows. There are instructions here but I run into the error described in the comment below it. There doesn't seem to be a reference anywhere for how one might go about doing this process.

I am targetting Microsoft Visual C++ 2010 Express. It looks like I need Perl and the Windows SDK as well - how do I go about this process?