How about this:
SELECT Max(DISTINCT gl20000.trxdate) AS LatestTrxDate
, gl00105.actnumst
, gl00100.creatddt
, gl00100.actnumbr_1
, gl00100.actnumbr_2
, gl00100.actnumbr_3
, gl00100.actnumbr_4
, gl00100.accttype
, gl00100.pstngtyp
, gl00100.actdescr
, gl00100.accatnum
, gl00100.tpclblnc
FROM gl00100
INNER JOIN gl00105
ON gl00100.actindx = gl00105.actindx
LEFT OUTER JOIN gl20000 AS gl20000
ON gl00105.actindx = gl20000.actindx
GROUP BY gl00105.actnumst
, gl00100.creatddt
, gl00100.actnumbr_1
, gl00100.actnumbr_2
, gl00100.actnumbr_3
, gl00100.actnumbr_4
, gl00100.accttype
, gl00100.pstngtyp
, gl00100.actdescr
, gl00100.accatnum
, gl00100.tpclblnc
HAVING ( Max(DISTINCT gl20000.trxdate) BETWEEN
CONVERT(DATETIME, '2014-04-01 00:00:00',
102) AND Getdate() )
OR ( gl00100.creatddt > CONVERT(DATETIME, '2014-04-01 00:00:00', 102) )
ORDER BY gl00105.actnumst
I think it will give you every account created after 4-1-2014 or used in a transaction since 4-1-2014 regardless of when it was created.
Kind regards,
Leslie