-- 0: filename -- 1: filesize -- 2: date -- 3:format -- 9: comment -- 13: custom tag -- 16: sample rate -- 17: channels -- 19: duration -- 20: bitrate -- 24: custom column 1
for i = 0, 30 do -- arbitrary limit
local val = reaper.JS_ListView_GetItemText(file_LV, 0, i)
Msg(i .." = " ..val)
end