CREATE TABLE #test(string varchar(55))
INSERT INTO #test VALUES('<![CDATA[deLastName,uSKt133Ii]]>')
                       ,('<![CDATA[deFirstName,hq1t]]>')

SELECT * FROM #test

SELECT 
SUBSTRING(string,CHARINDEX('CDATA[',string)+6,CHARINDEX(',',string)-CHARINDEX('CDATA[',string)-6) result1
,SUBSTRING(string,CHARINDEX(',',string)+1,CHARINDEX(']',string)-CHARINDEX(',',string)-1) result2
FROM #test