Hard currency for local/statutory reporting

Hello experts.

I have a question : it is always said : "Typically the same as the currency of the country of the company code." for the company code currency.

In order to produce statutory reporting but is it possible to choose the CC Currency which is not the currency of the country and use the hard currency (third) to produce statutory reporting ? Is there an issue to convert exchange rates ?

To sum up, can we produce statutory reporting with the hard currency (with exchange rates conversion) and what is the difference between using "local" (used day to day) currency as Coco currency and using it as hard currency ?

Thanks a lot,

Abdel