[Update: See Visual Studio 2010 Native Multi-Targeting]
Developers, if you use VC Build Hook and/or need the same capability in Visual Studio 2010, please let Microsoft know by voting for a fix (https://connect.microsoft.com/VisualStudio/feedback/details/570466/vs-2010-native-build-cannot-produce-ansi-response-files). I’ve written before (and here) about the problem. I think it is possible to hack a third party solution, but by far the best solution is for Microsoft to add back the ability to produce ANSI response files in service pack 1.