Excluding certain records on Data Load

Hello,

I'm loading records in Data Load Mgr, but would like to exclude a small number (6 records) based upon their unique 'PS #" assignment.  After searching this forum, I think I need to use the "where not" command in my script.

Here is the script I created using this command.

This yields an "Unknown Statement' error.  I'm sure it is just a syntax, or command placement error,

Can anyone help, please?

Much appreciated!