Code DSP audio

I need you to develop some software for me. I would like this software to be developed using C or C++. Digitally emulate the analog functionality of an audio filtering device. The purpose is to replicate the behavior so it will be virtually indistinguishable if the audio is going through the original device or the digital emulation. The characteristics of the analog circuit will be measured and provided to the developer. The end result should be a device that digitized the input of analog audio, applies the filtering characteristics, and outputs an analog audio out. The developer will have to communicate with me during the course of the project for device selection, attributes of the the device and in order to gather data on the original circuit to emulate it better.