C#: How to access an Excel cell?

Question

I am trying to open an Excel file and populate its cells with data? I have done the following coding so far.

Currently I am at this stage with the following code but

Answer 1

How I work to automate Office / Excel:

1. Record a macro, this will generate a VBA template
2. Edit the VBA template so it will match my needs
3. Convert to VB.Net (A small step for men)
4. Leave it in VB.Net, Much more easy as doing it using C#