Cloning a Windows machine and import into Boot Camp
This question on Super User may be of assistance.

It looks like you should be able to do a standard Bootcamp install of Windows, then use the system restore feature to clone your existing setup over to the Bootcamp install.

It's not as straightforward as directly cloning from your PC, but it should still save a fair bit of time vs. doing a full re-install with patches, etc., particularly if you use a USB drive for the install (which Bootcamp can help you with, given an Windows Installer ISO and a USB drive).