Hi,
The '%' needs to be in the parameter value.
[Edit] You can concatenate using the following approach: WHERE NSCC_x0020_Subject LIKE @Search! || '%'
That said, I would highly recommend to filter at the "List" level by using a contains condition. This will perform much better.
[Edit] Even better in your case, you will use a "BeginsWith" condition at the "List" level.
Let me know if you have any questions.
Regards,