I am not sure whats the point of recreating a report in Tableau to then export it back to Excel.
You would add more value to end user if you can work along with them in order to generate a visual insight out of the data. Otherwise just keep doing it in Excel like it is happening now, it will be much more effective for you and the end user.
I really not sure if anyone will be able to help on that as Tableau's main feature is not to build tables with such amount of columns. Instead is to use visual cues to make you see and understand your data quickly.
Thanks for the reply.
Yes Tableau is visualization tool. I Tried to explain my client better. but they need this report only in tableau. I am Helpless .