![alt text][1]You can query the SiteAdmin database via the Excel Report Query Bulider as shown in the attached file.
There you would enter the query I suggested before:
select [User],max(START_TIME) as ''Login_TS''
from
(
select USER_NAME as ''User'' from [qcsiteadmin_db].[td].USERS
) AllUsers
left outer JOIN [qcsiteadmin_db].[td].SESSIONS_HISTORY ON [User]=SESSIONS_HISTORY.USER_NAME
group by [User]

[1]: /storage/temp/432-excelreportquerybuilder.png