Dynamic generation of xcconfig file in xcode 4

[P Joshi]

I want to dynamically set the build settings, specifically the header search paths, for a target. I intend to do so by adding a target which generates an xcconfig file that includes the search paths. I run this target first, followed by the target that actually uses the search paths and tries to obtain the by referencing the xcconfig file. This approach is not working. The xcconfig file is generated, but the build settings are not reloaded. Is this expected? Is it even possible to achieve what I am trying to do?

Thanks,
Pankaj