user define reports in windows application

Hello Friends,

i m facing very big problem in reporting actually i have created all reports in crystal report which is fixed if i want to do some changes then first i have to make changes in report after that rebuild it and replace the against of exe which is really to long job.. client wants that he wants to make format according to his requirement and drag the table columns in report according to his requirement .. now i don't have any idea how would i provide to him this facility in windows application (C#). if you have any idea and any tool for this thing so please let me know .. its really appreciate to you.. please help me and give me guidance to solve this problem

 

thanks in advance