To fly below cat I minima you need:
A suitably equipped aircraft
A suitably equipped airfield
A suitably qualified crew
An organisation with appropriate training manual and performance monitoring programming
Approval from the regulator for all the above.
The last is I suspect the problem. EASA regulations for below Cat I approached amounts to a massive manual (PART-LVO). Military regs from a quick search through the MAA...Zip, zilch. You cannot approve something you don't regulate. It might happen through another means that's not public of course