unfortunately the answer is that export makefile does not exist in any version of VS since 6.0 (98) and there aren't any plans to change that. the reasons behind losing this feature in 7.0 (2002) are varied, but most important was the lack of resources (time) to re-implement the work in the new project system (the 7.0 project system was a near-complete re-write, in order to get certain features and fit into the "all-languages-in-one-shell" VS). also figuring into the decision was the feeling that we weren't able to produce good quality makefiles (if you've ever looked at any of the exported makefiles you may agree) and that the command-line devenv /build would somewhat alleviate any pain. (vcbuild.exe may also help alleviate this even further; it has been designed specifically with use in a build lab, and we use it here to build over a million lines of code every night, so hopefully it is getting reasonable "exercise" to ensure that it is useful and stable).
VC projects will not support msbuild, and msbuild will not ship official support for VC. i'm not sure how much i should really comment on this, so i'll just say that practical considerations (time/manpower) precluded doing this work in whidbey.