how do I maintain my conditional formatting when filtering cells?
 

I have set a conditional format to shade cells red when the milestone date is
overdue (i.e. greater than today's date), and to shade yellow if they are
approaching (i.e. within 20 days of today's date). However, when I filter the
worksheet, the conditional formulas remain in the reletive cell (e.g. always
in row 148), even if I change it to be an "absolute" cell reference ($I$148).
I want the conditional format to remain constant in each particular cell,
despite where it's location is after filtering data. Is this possible?