Select Item query

I am using Studio X. I have an excel sheet and trying to choose each item from excel sheet in a drop down box in a web page (using Select Item). One of the value that I have in excel is not an item that is listed in the drop down menu. How do I identify that at run time and skip to next item. I tried using “Check App State” resource mapping to that particular field, but it did not work.
Appreciate your help.