How do I Multiply an Indicator by a Vector?

["BL" <blee7@xxxxxxxxxxxxxx>]

I have a custom indicator that I would like to 1) Display only the most
recent 20 days of the indicator and 2) weight each of these 20 indicator
values by a different numerical weight.  For simplicity, assume the value of
the indicator for the current day would have a weight of 20, the value of
the indicator for the previous day would have a weight of 19, etc down to
the indicator value 19 days ago having a weight of 1.

I assume there is a quick, one-line command I can employ to "weight" n-days
back, like matrix algebra, instead of doing each daily calculation
individually. I'm using v6.52.

Thanks, Brian