Custom Tagging EXIF fields - hardware and software solution required. Preferably C# on Raspberry

We are looking to custom built a solution that will typically help us read/write custom data captures (through barcode scans) to the EXIF fields of JPEG files in-camera. The ideal solution would be a microcontroller (that runs a C# source code) which would be attached to the camera and after scanning a barcode, would write this barcode to the EXIF field of the JPEG file in-camera. Part of this project is also a Windows software which will be able to read this custom captured data and export them as a Excel CSV file. More details would be disclosed to the Freelancers that we will shortlist.