I have a spreadsheet with sales $ in Column I and a list date in column O.
I would like to apply conditional formatting to column O to highlight cells
whose date is 2007 or newer.
Select column O and enter this formula in conditional formatting formula
field:
=YEAR(O1)=2007

I would then like to apply to column I and highlight
cells whose sales $ are amongst the lowest 10% and who are not already
highlighted in Column O.

Please specify in detail what do you call "amongst the lowest 10%". Whose
sales are less then 10% of total sales? Or something else?

Regards,
Stefi