If there is proof that a witness committed perjury it could be helpful. The case may have other evidence that could prove the elements necessary for the case. Good luck.
This answer is only for informational purposes and is not meant as legal advice.
Perjury is specific statute. One does not commit perjury just because they told untruths. If the prosecutor believes the person lied under oath about a material fact, he will dismiss your case and arrest the witness. If everyone agreed with you would not be adefendant