Fill a field with content dependent on the content of another field

I would like to have certain fields automatically filled with content dependent on other fields. For instance, for the “Magazine article” reference type, I would like to enter the name of the magazine, and have the ISSN automatically filled witht the ISSN for that magazine, which would always be the same; or the in in the “language” field, have it filled with the language in which that magazine is printed, which will be always the same. Or for a certain author, have the “Author’s address” field filled authomatically with