From: Rabbi Moshe Sofer
To: Rabbi Shaul Landau
When a man's Hebrew name (Naftali) and secular name (Ziml) are etymologically unrelated, the formulation in the get depends on origin: if both were given at the bris, write "Naftali, known as (mekune) Ziml"; if Naftali was self-selected later in life, write "Naftali, called (d'miskari) Ziml" and give a second get as a precaution. The Chasam Sofer also recommends investigating the name's provenance to determine the proper Hebrew equivalent of Ziml, noting conflicting traditions in the standard reference works.
Source: Shu"t Chasam Sofer EH II §21