If either parent is still in that county, you cannot get it moved. Also, jurisdiction for custody follows the child, so if she is still in that county with the child, then you cannot get it moved. If neither of you nor the child are in that county, you can file and ask that jurisdiction be moved for custody to the county in which the child lives, and as that child support be moved to your county, but honestly, it's a lot of work for move in the same state, and you'd have to hope the current county will give up jurisdiction.
You may want to talk with an attorney and find out if you can get it moved due to a conflict of interest.