However, if you have a RangeToRegex function, I expect it to support alphanumerical, not only numerical then.

```bash
mt@kodachi:~/libbash (libbash::master)$ RangeToRegex 1,2,5,10-20,a-v
Unkown value (a-v) in range:
1,2,5,10-20,a-v
```