Can I change the "user_login" slug to something else?

Does anyone know if there is a way to change the required “user_login” slug to something like “M-login”?

Basically, I want to import a csv file of new users from a different platform, but my client’s import file uses the header “M-login” rather than “user_login” and “M-email” instead of “user_email”, etc..

I realize the easy answer is to change the clients header of “M-login” to “user_login”, but that is not going to work for my client…

Is there a way to achieve this change to these required fields through phpMyAdmin? If anyone knows a way and can walk me through the steps, I’d really appreciate it!