using libs installed with macports to build a tarball

Hi I'm trying to build qjackctl (a gui for Jack audio connection kit) from its source tarball. qjackctl uses qt4, so I installed qt4-mac from macports (successfully) but the configure script of qjackctl can't find it. Do I have to set up an env. var in my .profile file? Rémi Leopard, Macbook 2GHz Intel Core 2 Duo