help with visitation on a child kept from me??????????

[lostsoul]

for starters I live in oregon and have a child that is almost 10,who lives in washington.  The mother has kept this child and his whereabouts from me his whole life.  When i divorced her it was in oregon and they wouldnt do anything with the child as they didnt have jurisdiction as he was living in another state.  In 2000 the grandparents went to court and got custody and by saying my whereabouts were unknown they didnt have to have me served(even though i was orderd by the state to pay child support).  Even when i would call them they would lie and say they couldnt tell me where my son was cause the mother didnt want me to know.  In 2007 i went for a paternity test(after i found my son and learned of the custody order) but withdrew it at the hearing based on info i received the day before.  At that time i requested visitation and the judge said i needed to file a parenting plan.  I have what i think is the papers but am unsure if they are what i need and what to do next.  I just want to be able to see my son and eventually get custody of him what can i do.  Thank you john