Extracting bits of a syxdump_pos byte?

I found some posts here with similar thematics, but it did never seem quite covered for my application case, so I thought I’d start a new one..

I am reading and processing a program parameter dump from a hardware synthesizer, and some of its parameters are woven into one single byte of the dump (for example the activation and polarity of certain envelope parameters can be (de-)activated/polarity-switched). And since I want to control these parameters from a hardware controller, I need to read and display the, currently set, values on the controller’s displays. 

That is why I am calling syxdump_pos=x:y a lot… It would therefore be perfect to have something like syxdump_pos=x:y:z to call for subdivisions/single-bits.

I guess the way to achieve this would be altering the MBNG_EVENT_NotifySyxDump function in in the mbng_event.c file, but I’m not sure how to approach this… Has anyone else ever done anything similar? Or maybe found another way around it?