Integrating exported code from gen into Qt framework

We are building an app in C++ with Qt framework and qmake, and we want to embed into it some sound generators that we have created using Gen functionality from Max MSP.
We have tried to include the exported files generated by the 'exportcode' message in Max, into our Qt project but we are getting 'undefined reference' compilation errors from the functions in the files in the gen_dsp folder. Has anyone got any experience with using gen exported code with qmake? What would be the steps to integrate the exported code into Qt or in general using cmake (not just for JUCE)?
We were also wondering if it is possible to make a library from the gen_dsp files. We are using multiple sound generators that use these common files, so it would make sense to have a library.