3-2 Engineering Program Questions

Hello, I am a rising sophomore at an affiliated college with Columbia University and it’s SEAS department. I am pursuing the Pre-Engineering dual-program with the goal in mind to attain an applied math degree from Columbia SEAS. In addition, I am interested in finance and economics and have been taking those courses at my college. I am interested in pursuing a financial-economics/economics major/concentration at Columbia College, in addition to the applied math degree offered by SEAS. I understand, logistically, that would be difficult to manage given course load and/or available transfer credit. But, I am concerned that this would not be feasible as I would only be a student at SEAS, not Columbia College. Are SEAS students able to double major with an engineering degree and a degree from CC? I understand there is the IEOR department with a concentration in Financial Engineering, however that program does not interest me as much as the Applied Math route. In addition, I am interested in hearing past Columbia Engineering students experiences pursuing careers in finance.
Thanks for your time and help.