iMacros, conditional based on .CSV data

I'm trying to get iMacros to enter data from a C# generated .CSV file into a webpage. If one of the fields remains blank, iMacros errors out with

"Entry [] not available [Box has 804 entries], line: 24 (Error code: -924):"

How can I set iMacros to conditionally enter data ONLY if that .CSV column has data in it?

Here's the code:

TAG POS=1 TYPE=INPUT:BUTTON FORM=ID:procform ATTR=NAME:next
TAG POS=1 TYPE=SELECT FORM=ID:procform ATTR=ID:field_900022 CONTENT=$

I tried to use an EVAL command, but it didn't work:

SET !$ EVAL("if (\"$\" != " ")    
    TAG POS=1 TYPE=INPUT:BUTTON FORM=ID:procform ATTR=NAME:next
    TAG POS=1 TYPE=SELECT FORM=ID:procform ATTR=ID:field_900022 CONTENT=$;

Note: using iMacros free firefox add-on & Visual Studio 2015 C#. I used a space (" ") in the c# program to hold the CSV field (i.e. "data, data, , more data"). It can very well be another character. Thanks