Without additional information on just what the lender means by "tapping in to taxes you paid 4 years ago" it would be difficult to answer your question.
Did they give you any clue of what they mean by this?
They mean that since I paid state mortgage tax on my property only 4 years ago, he can use this tax already paid to reduce my refinance state mortgage tax.
Thank you for the additional information. I will post your question on the board to see if someone knows the answer.