SPSS means? Don't think I really need to know, but when you post abbreviations and don't identify what they stand for, it can lead to miscommunication.
Presumably, you can use your imported data to create a table where you have a record for each code in one field and the language name in another. You can then define a value list to list values, selecting the code field for the first field (Primary) and the language name field as the secondary. This then can be used in a drop down list that will list both the code and the language name while the value list is deployed, but what is entered when the user selects a language will just be the code. If you want to also see the language name, define a relationship from your layout's table to this table of language records and add the language name field from this related table, locating it next to the code field that you have defined as a drop down. Or you can use the pop up menu option instead of drop down list and not need to add this additional field.