Filling Excel file using C#

I have been writing a program for my business using winforms & c# for generating invoices.

I want to fill up values to an excel sheet which is pre-formatted. What is the easiest way to do this ?

Here开发者_运维百科 are the screenshots..

Thanks..

I've had great luck with this tool: http://npoi.codeplex.com/

I've used this open source library - http://code.google.com/p/excellibrary/

Did the work for me.

Take a look at Templater. It was designed for this kind of use case.