Is there any way to create a macro to keep doing nonlinear regressions?

[elkprj]

Is there a way to create a macro keep doing nonlinear regressions 'till the sum of all regressions give very close points to y results for given x values. It would be better if it create trigonometric regressions like sine or cosine regressions, I do not know whether automatic trigonometric regresion ispossible or not though. I have added a sample file what I would like to achieve, it is not in the US excel format though. Thanks for any help in advance.