The actual date of filing a case is significant in order to determine whether or not prescription has already set in. For instance, a person may no longer be prosecuted for a crime if the criminal complaint/information was filed beyond the prescriptive period. The same holds true in civil cases. One's cause of action against another must be filed within the allowable period, otherwise, his cause of action will be barred by prescription.
Regarding your inquiry on perjury, the following are the elements of perjury: (a) that the accused made a statement under oath or executed an affidavit upon a material matter; (b) that the statement or affidavit was made before a competent officer, authorized to receive and administer oath; (c) that in that statement or affidavit, the accused made a willful and deliberate assertion of a falsehood; and, (d) that the sworn statement or affidavit containing the falsity is required by law or made for a legal purpose.
You may be referring to the Complaint executed by the complainant wherein he declared, under oath, that he is a resident of a certain place when in truth and in fact he is a resident of another place. If your friend is certain that the complainant is really a resident of some other place and that he lied about his residence willfully, your friend can charge him before the prosecutor's office for perjury. Your friend can probably look for other documents executed by the complaiant wherein he declared that he is a resident of another place.