non-linear estimation ols

[megreeno]

how i can estimate non linear equation?
i have not menipulate my data yet, sohuld i do it by excel

this is the equation:

and it has to be estimated by the first difference except for the varibal (open)

〖 lnCPI〗_t=α+ β_(1 ) ln⁡(NEER) +β_(2 ) ln⁡(WWPI)+β_3 OPEN+ε_t


thanks

[EViews Glenn]

I'm afraid that I don't understand the question. Why do you believe that this equation is nonlinear in the parameters? Where does "first difference" come in here?