[C] Add more scopes for variable assignment

[ketpain]

Problem description

I really love this program. I've looked around and it seems I could maybe improve scopes myself but I feel like it should be shipped with the program.

Preferred solution

Would like to have control of self defined variables and such

Alternatives

No alternatives really

Additional Information

Thank you for the amazing and lightweight program.

[michaelblyons]

Maybe try out #1831?