ok, if it's dynamic, it a pain, but doable. so much of it depends on the page that is presented with the listof files, because you have to extract them all out.
i've done it like this:
In my case, i was downloading csv files.
I've used a script task to read a web page into a string.
i then parse the string with a regular expression to get all the a href="somefile" links.
i personally had to tweak the links because they were all relative, and i needed absolute:
ie the link said <a href="Invoice_2015_10_01.csv">Invoice_2015_10_01.csv</a>
but i needed the full path of http://website.com/Subdirectory/Invoice_2015_10_01.csv
that list went into a datatable, that i passed to the next script task; it could have been a delimited string, or a string array or a list of string, but that's just the way i did it.
the next item was a script task that downloaded each file in the datatable.
Lowell