Download and install LogParser from here:
https://www.microsoft.com/en-us/download/details.aspx?id=24659
Then create a text file query.sql containing your query
SELECT distinct
replace_str(replace_str(to_lowercase(cs-username),'0#.f|ldapmember|',''),'0#.w|','') as username
FROM C:\inetpub\logs\LogFiles\*.log
WHERE cs-username > ''
AND date >= '2017-01-01'
Then execute the following command
C:\Program Files (x86)\Log Parser 2.2\logparser file:"query.sql" -i:IISW3C -o:CSV -recurse > c:\temp\usernames.csv
(note: path to LogParser may vary on your system, it may also be handy to add it to the %PATH%)
Learn more about LogParser here:
https://technet.microsoft.com/en-us/scriptcenter/dd919274.aspx