In each product, there’s a section for parts. And each part can have it’s own export ‘formula’. This means that you can write out your excel file, using comma’s to separate each column.
For example:
Value 1,Value 2,Value 3,Value 4
This would create an excel file with 4 columns.
To see this go to:
Settings > Catalog > Products
Then, click on any product in the list. Next, go to the parts tab, at the top and there you’ll see each part of that product. Click on the down arrow to see the export formula box, where you can type in a formula using variables from the right side (the blue links) or by typing in your own value.