Normally both parents are required to provide the other parent with a current mailing address, phone number and email address. The one exception to this would be if one of the parents has a restraining order against the other preventing any contact. There is not really a form to file. I am surprised that the court did not require that of both parents. You can take a blank motion and simply modify it to request the disclosure of the address. Best wishes.
The information provided in this answer does not create an attorney-client relationship and is not considered to be legal advice.
This is completely stupid. The idea that a parent would move and not tell the other parent drives judges crazy. Tell your friend to send a police note to the re-located parent asking for the information. If that fails, tell the same friend to talk to a family law attorney about the situation.
In no way am I offering you legal advice, and in no way has my comment created an attorney-client relationship. You are not to rely upon my note above in any way, but insted need to sit down with counsel and share all relevant facts before receiving fully-informed legal advice. If you want to be completely sure of your rights, you must sit down with an experienced criminal defense attorney to be fully aware of your rights.
There is no statute that requires parents to provide the other with their address. However, most judges believe (except in protection order cases or cases where someone's life has been threatened) that both parents should know a physical address for the other parent. Not providing an address will be frowned upon by the judge or magistrate. If I have a client who is behaving that way, I correct the behavior very quickly.