SQL IF statement for unique rows

I am working in Excel and Im trying to make an if sql statement:

="INSERT INTO Roles (Role Type, Role, Trade) VALUES ("&A1&", '"&B1&"');"

In my C column I have a numbers in the first 13 rows and then I have string in rows 14 to 19. I am trying to make an If statement so that the first 13 rows are treated as a number and rows 14 to 19 are treated as a string. Thanks in advance!