This article might help:

http://www.databasejournal.com/features/mssql/article.php/3112381

Ok...I'm no expert on credentials and proxies, but I have gotten this to work.  The issue is that there is encrypted secrets in your package.  Packages without passwords don't have...

Just to make sure, the only thing that should be appearing in the expression box is:

@[User::File_Path]

Where "File_Path" is the name of your variable.  You are adding this value to the...

I think so...It might be easier to work this out outside of the foreach loop, then drag it to the foreach loop container.

1. Add a data flow task to...

The Wrox book is awesome.   I'm not sure this task is well handled in it, though.  I have had to do similar things...here is how I would approach this task...