Using NULLIF in SQL*Loader

I am trying to load an Oracle7 database with data from a text file. One of the columns contains either numerical or character data. I would like to ignore the character data, and only load the numerical data (between 0 and 5).
I placed a statement in my SQL*Loader '.ctl' file like this:

cls POSITION(*) INTEGER EXTERNAL NULLIF (cls NOT BETWEEN 0 AND 5),

I get the error:

SQL*Loader-350: Syntax error at line 10. Expecting = or "<>", found "NOT".
cls POSITION(*) INTEGER EXTERNAL NULLIF (cls NOT BETWEEN 0 AND 5),

Does anyone see the problem here? Received on Wed Sep 17 1997 - 00:00:00 CDT