C# script in SSIS package

Question

I need to create a task in SSIS that will check for the existence of a set of files before allowing execution of the remainder of the package. The method needs to read the file name from a database table (could be 10 - 50 files), check if it exists in a certain directory, then write a record into a validation table with the date and a simple Pass/Fail.  I'm a c# nubie, so this is challenging.  Somehow I have to to loop through the table contents based on a file group (query or stored proc) and check each one. Ideas or just back to class :-)?