Delete row when data is numeric?

I'm using a DTS package to import a large CSV file. There is a particular column that contains text or numbers. I want to delete the row if that column has a number, I've used IsNumeric in the selection portion of the statement, but can't figure out how to use it as part of my where clause.Never mind - i got it right after I posted... it has been a long week and I'm not thinking clearly any longer: Where IsNumeric(columnName)=1