"James
It can be done. Can't remember who it was but someone was working on one where it told you what tyre to select based on the amount of fuel used in the stint. Not sure if they will make it public or not once they get it finalised, but it is a great idea that might bring more strategy into the game.
And yes we are a very pretty, helpful & happy bunch here in the iGP community, no matter what time you call in there is always peeps online :)
i have done some thing similer to my spreed sheets which now has many additions to it.