Paintbar back in time

["Phil Kobierowski" <phil@xxxxxxxxxxxxxx>]

(Some of you may have tried to help me but I'm still stumped on this). 

I have a paintbar with inputs of a date and time and a number (X).  I want
to paint the bar of the date and time (easy enuf) and also all bars that
are multiples of X bars before and after it. So if X is 5 I want to paint
5, 10 15, etc bars before (to the beginning of chart) and after the one of
the input date and time. I can do the bars that come after but need help on
painting the bars that come before. (I know there's a findbar function but
that only looks back in time.)

Any help appreciated.