With mySampledata(id,SomeComment)
AS
(SELECT 1,'- aaaaaaa 02/20/2002 jjjjjj sddsdjjjjsdsd sdsds
- asdlajsd fjsdfjkdgn dsjbfks, dfjksflml,fsf,f sdfsdf 9/3/99 sjdfnsdnf sjdfoisofn
- sdkfjos fjsdopfj uyro dlsfl 02-02-02 sflnsldfn sdkflsn
- fdklnsdlnf 02-02 fjsksngjk
- sdkflsdnfl 02/02 hisfdhiif sdjfsdkfk')

SELECT mySampledata.*,
myfn.* ,
Case when IsDate(myfn.Item)=1 THEN CONVERT(datetime,myfn.Item) ELSE NULL END AS PotentialDate
FROM mySampledata
CROSS APPLY dbo.DelimitedSplit8K(SomeComment,' ') Myfn

With mySampledata(id,SomeComment)
AS
(SELECT 1,'- aaaaaaa 02/20/2002 jjjjjj sddsdjjjjsdsd sdsds' UNION ALL
SELECT 2,'- asdlajsd fjsdfjkdgn dsjbfks, dfjksflml,fsf,f sdfsdf 9/3/99 sjdfnsdnf sjdfoisofn' UNION ALL
SELECT 3,'- sdkfjos fjsdopfj uyro dlsfl 02-02-02 sflnsldfn sdkflsn' UNION ALL
SELECT 4,'- fdklnsdlnf 02-02 fjsksngjk' UNION ALL
SELECT 5,'- sdkflsdnfl 02/02 hisfdhiif sdjfsdkfk')
SELECT mySampledata.*,
myfn.* ,
Case when IsDate(myfn.Item)=1 THEN CONVERT(datetime,myfn.Item) ELSE NULL END AS PotentialDate
FROM mySampledata
CROSS APPLY dbo.DelimitedSplit8K(SomeComment,' ') Myfn