@mageesa Today I went to the police station to receive el certificato de domicilio. At first they told me I should follow the procedure for extranjeros, and gave some URL where I can start. Then an Argentine friend told me I should have asked for el certificado de supervivencia, not de domicilio. These certificates are equivalent for some purposes but the difference is the police doesn't seem to like to give out the domicilio ones, but if you ask for supervivencia, they give it to you right away without any special procedure for extranjeros.
So I went the second time. A police lady made it for me but did not hand it to me. She said since I don't have a DNI she will mail it to by the indicated address with Correo Argentino. I was disappointed but said ok I'm going to wait.
Then I told what happened to my friend and he said it was unusual. Offered to accompany me. So I went the third time. And this time with the company my Argentinian friend the police gave it right away. All they needed was an ID and a rent contract.
All three visits happened today. I don't understand why they have to act so dodgy about these certificates. Anyways, I'm happy to receive one and perhaps my story can help somebody else.