User name in different languages in table ADRP

Dear colleagues,

I have a requirement to store SAP user name in several languages. And as far as I have noticed SAP can do this, because in table ADRP there's a field NATION, which is a key field. My problem is that I can't find a standard way to enter user name translation into SAP. Neither I see this possibility in transaction SU1, nor in SU01 etc.

Can someone advise standard transaction or report to manage SAP user name translations?

Thanks a lot in advance for your help.

Best regards,

Andrew.