Starsector 0.97a is out! (02/02/24); New blog post: Simulator Enhancements (03/13/24)
Wyvern is 100% correct about the math.
Excel works great -- don't import/export, just open and save
I suggest OpenOffice.
On a Mac; my tool of choice is CSVEdit, which is lightweight and handles everything Starsector throws at it like a champ so far.