When using the SQL 'Like' statement, you can indeed use wildcard to make partial matches. This is however general SQL behavior and not specific to Lansweeper. More information about this statement can be found
here. As for the original issue, we were not able to reproduce this behavior. When adding the following to the query, the expected results were returned:
Using the SQL statement itself:
where IPAddress not like '10.2%'
Using the editor and adding this to the IPAddress 'criteria'-field:
Not Like '10.2.%'
As you mention that the query is being altered by the report builder, this could indicate that there is another SQL error in the statement which 'breaks' the SQL statement. If you could provide the full SQL statement (or send it to support@lansweeper.com), we can troubleshoot this further.