Seemingly everyone here has forgotten about the version byte used in addresses!
Create a new address over RPC, decode the base58 into hex, and the first byte will indicate what network you are on.
https://en.bitcoin.it/wiki/List_of_address_prefixes If the item isn't on this list, just follow this procedure with your whatevercoin, and you'll get the address byte.
Clever.
I think I missed an important information: I'd like the process to be done automatically in a script.
The ideal think would be that if I add a new coin wallet in my wallet directory, the script would be able to extract the wallet amount and its unit.
For example, if I create a Darkcoin wallet there and mine some coins, I would get from the script something like: "234.56 QRK".