Xcode IDE how to define a path variable in project

How do I create a user defined path variable. For example I have a project that uses a

lot of library code (Boost etc.) in a "Common" Directory. I have a lot of project relative

header search paths that look like ../Common/SomeLibrary/someHeaders



I recently moved the project a directory level down, so I need to edit all of these to

../../Common. What I'd like to do is define a User-Defined variable something like

COMMON_CODE_PATH = ../../Common



I tried this but I immediately get header not found errors. What special incantation

do I need?



Thanks,



Wayne Anderson

waynemaciosdev@gmail.com

wayne@truwayllc.com