>Not sure if this is what you want but if you are trying to display a 0 when the numeric is null you might try something like this.
>declare variables
>test = ''
>OR
>test = 0
>
>retval = iif(empty(test)and type('test') = 'C',".NULL.",NVL(test,0))
>
>?retval

No, we had someone who wanted to substitute NULL for an empty value, and then discovered that for numerics, 0 is empty, but not null.