Perjury By Ex Wife

My ex wife lied to the judge in order to get higher child support from me. Our daughter was living with her grandparents and my ex told the judge this morning that she was back with her as of last night.

I called the Dept. of children’s services and they said it’s not true. She will be going back next week. How can can I bring perjury charges against her. What forms do I use? Also, can I get the CS lowered?

Any help would be appreciated.