I assume "tool" means the TurboTax (TT) program. You enter the interest paid by treating the 1099-E as your own. TT does not ask for your SS#. Lying to TurboTax to get it to do what you want does not constitute lying to the IRS. The 1099-E is only an entry tool. There is nowhere on the forms to tell TT or the IRS that you are just a co-signer. You handle that if you get an IRS inquiry. That's unlikely. This is a common situation.
