Excel-file with customers and budget

We need help in making an Excel-file in which a list of customers are added. For each customer there are cells with value and other practical details and the timeperiode the contract is for. We would like the excel file to automatically create a new sheet which the customer is copied to and the value of the contract is displayed for each customer pr month and year and the total amount from all the customers. Likewise we want a similar sheet for posting expences for different suppliers and a sheet with the total expences for each category of expence pr month and year. We also would like a sheet that displays the to-do list for each customer displayed. The list shall be displayed on a calender. On a final sheet key info from the other sheets can be displayed.