Store Commander's integrated CSV Import tool allows you to integrate new products or modify them in several languages in just a single import process.
Indeed, the mapping options allow you to select the language you would like to create or modify your products.
The above screenshot lists all database fields that you can import in several languages.
Your CSV file will as usual need to include a column per field and per language.
The choice of language is available in the 'Options' column as shown above.