Average of several series which contain the smallest values

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I would like to make an average of n series which contain the smallest (but above zero) values among N available time series. And this averaging should be made for every period separately, because different series could have the smallest values in different time periods.
I could do this in Excel with function like: =AVERAGE(SMALL(RANGE,{1,2,3,...n})) where RANGE is N, but I would like to perform this computation in EViews. Any help will be appreciated.