Hi Saro,
According to your description, you want to add polynomial trend line to a column chart, right?
In Reporting Services, we can add calculated series formula (like Moving average) for the chart. In your scenario, if you want to add polynomial trend line to chart, it cannot be achieved currently. It is because the polynomial trend line is not supported
in current release of Reporting Services. We can find all the supported formulas in the drop-down list on the calculated series properties window. There is a workaround that we can calculate the values manually. For more detail information, please refer to
this blog: Add a linear trendline to a graph in SQL Server Reporting Services
For your requirement, I would recommend to submit it to the Microsoft Connect at this link
https://connect.microsoft.com/SQLServer/Feedback. This connect site will serve as a connecting point between you and Microsoft, and ultimately the large community for you and Microsoft to interact
with. Your feedback enables Microsoft to offer the best software and deliver superior services, meanwhile you can learn more about and contribute to the exciting projects on Microsoft Connect.
If you have any other question, please feel free to ask.
Regards,
Shrek Li