Re: Warp speed calculations in Excel
There are probably dozens of warp factor scales worked out by fans over the last 40 years for every series. Find one appropriate for ENT, perhaps one that's commonly accepted by those who explore such things (like the guys in the Trek Tech forum), and use it as your model.
After you write the story, someone will eventually pop up and say "but such-and-such says..." and you can say "I used this particular scale here."
Curly: Moe, Larry, the cheese! Moe, Larry, the cheese! (Horses Collars, 1935)