If I buy a Cover Song license, will I be covered for my translation?
Unfortunately, no. Cover Song licenses do not cover any forms of translation unless that translation is an official version approved by the original copyright holder. Regardless of if you put the lyrics in through Google Translate or you have a native speaker translate a grammatically correct version of the song, it is not permitted by a Compulsory Mechanical License. This is because any alteration to the original lyrics is a derivative work that requires direct permission from the copyright holders, and a Compulsory Mechanical License does not get that direct permission.
What is a Derivative Work?
Why does my Cover Song status say "Custom Required?"
Compulsory Mechanical Licensing Law
Custom Licensing Services