Export Excel to Txt

I have googled "Microsoft.Office.Interop.Excel" and I have googled things similar to the title of this question with no sufficient luck.

What I am trying to accomplish, is programmatically opening an excel file (without actually opening it, just pointing to it) then saving the columns/rows to a txt file. I want to do light formatting, such as removing certain columns or values from the txt file.

Any help would be most appreciated.