How do I reply to letter from and attorney, when I know the SOL has expired on a debt.

I posted a similar question earlier ,im not sure i did it right,please excuse me if im making it worse by asking again. I have gotten a letter form a debt collector ,who is retained by the original creditor, They have given me 30 days to reply and dispute the debt and they will obtain the validity of the debt I allegedly owe them money ,but that the last time payment was made on this card was over ten years back, in 11/2001 and charged off 5/2002 so the CC debt is a expired SOL and they would loose if it went to court,providing i went as well , I have proof it was charged off on these dates, I want to avoid going to court, I am disabled and physically and stress wise it ill only make me more ill needlessly.What should i say in my reply to the debt collector , that I am disputing the alleged debt entirely or do i also need to ask for debt validation, the letter implies that will happen if i dispute, but will DV show them they arr working with an expired SOL for KY of 5 years ,I read they are not suppose to try and sue me if they already know this and I have a hunch they might know as the letter states no layer from their firm is aware of my files circumstances.If they check and see the last date of payment will be over ten years and should not contact me anymore knowing they cant sue unless they are telling me they cant sue, in any case Id like to get a certified letter out with a return receipt ,asap but need help in what I should say in the letter,and not to incriminate myself.Um not one to ignore my debts this only happened because I had a life changing illness and was unable to return to my lucrative job i had for years.thank you and I hope you will please help me as I will do for others when I can.