don't you have to query for it first?

http://www.vistax64.com/vb-script/174244-look-up-when-password-last-set.html

look at the part

objCommand.CommandText = "SELECT Name, whenCreated, pwdLastSet FROM
'LDAP://dc=corp,dc=acme,dc=local' WHERE objectCategory='user' " & "AND
sAMAccountName='" & strUsername & "'"
Set objRecordSet = objCommand.Execute