How to find avg of HL of all days in previous week?

#1
How to find avg of HL of all days in previous week? For eg am on 13-Aug-2019.. I am looking at getting the last (prior ) weeks high ,low price each day.. and then take an average .. Assuming it could be a 2-3-4-5 day week (prior week) how do i code it in Amibroker.